[ { "id": "authors:4k87y-rze66", "collection": "authors", "collection_id": "4k87y-rze66", "cite_using_url": "https://authors.library.caltech.edu/records/4k87y-rze66", "type": "book_section", "title": "A Compositional Approach to\u00a0Diagnosing Faults in\u00a0Cyber-Physical Systems", "book_title": "Runtime Verification", "author": [ { "family_name": "Graebener", "given_name": "Josefine B.", "orcid": "0000-0002-1376-0741", "clpid": "Graebener-Josefine-B" }, { "family_name": "Incer", "given_name": "Inigo", "orcid": "0000-0001-7933-692X" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "

Identifying the cause of a system-level failure in a cyber-physical system (CPS) can be like tracing a needle in a haystack. This paper approaches the problem by assuming that the CPS has been designed compositionally and that each component in the system is associated with an assume-guarantee contract. We exploit recent advances in contract-based design that show how to compute the contract for the entire system using the component-level contracts. When presented with a system-level failure, our approach is able to efficiently identify the components that are responsible for the system-level failure together with the specific predicates in those components' specifications that are involved in the fault. We implemented this approach using Pacti and demonstrate it through illustrative examples inspired by an autonomous vehicle in the DARPA urban challenge.

", "doi": "10.1007/978-3-032-05435-7_24", "issn": "0302-9743", "isbn": "978-3-032-05434-0", "publisher": "Springer Nature Switzerland", "publication": "Lecture Notes in Computer Science", "publication_date": "2025-09-12", "volume": "16087", "pages": "438-456" }, { "id": "authors:vzzzx-dqa08", "collection": "authors", "collection_id": "vzzzx-dqa08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220715-744315000", "type": "book_section", "title": "Towards Better Test Coverage: Merging Unit Tests for\u00a0Autonomous Systems", "book_title": "NASA Formal Methods: 14th International Symposium, NFM 2022, Pasadena, CA, USA, May 24\u201327, 2022, Proceedings", "author": [ { "family_name": "Graebener", "given_name": "Josefine B.", "clpid": "Graebener-Josefine-B" }, { "family_name": "Badithela", "given_name": "Apurva", "clpid": "Badithela-Apurva" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Deshmukh", "given_name": "Jyotirmoy V.", "clpid": "Deshmukh-Jyotirmoy-V" }, { "family_name": "Havelund", "given_name": "Klaus", "clpid": "Havelund-Klaus" }, { "family_name": "Perez", "given_name": "Ivan", "clpid": "Perez-Ivan" } ], "abstract": "We present a framework for merging unit tests for autonomous systems. Typically, it is intractable to test an autonomous system for every scenario in its operating environment. The question of whether it is possible to design a single test for multiple requirements of the system motivates this work. First, we formally define three attributes of a test: a test specification that characterizes behaviors observed in a test execution, a test environment, and a test policy. Using the merge operator from contract-based design theory, we provide a formalism to construct a merged test specification from two unit test specifications. Temporal constraints on the merged test specification guarantee that non-trivial satisfaction of both unit test specifications is necessary for a successful merged test execution. We assume that the test environment remains the same across the unit tests and the merged test. Given a test specification and a test environment, we synthesize a test policy filter using a receding horizon approach, and use the test policy filter to guide a search procedure (e.g. Monte-Carlo Tree Search) to find a test policy that is guaranteed to satisfy the test specification. This search procedure finds a test policy that maximizes a pre-defined robustness metric for the test while the filter guarantees a test policy for satisfying the test specification. We prove that our algorithm is sound. Furthermore, the receding horizon approach to synthesizing the filter ensures that our algorithm is scalable. Finally, we show that merging unit tests is impactful for designing efficient test campaigns to achieve similar levels of coverage in fewer test executions. We illustrate our framework on two self-driving examples in a discrete-state setting.", "doi": "10.1007/978-3-031-06773-0_7", "isbn": "9783031067723", "publisher": "Springer", "place_of_publication": "Cham", "publication_date": "2022-05", "pages": "133-155" }, { "id": "authors:4xqya-s9m89", "collection": "authors", "collection_id": "4xqya-s9m89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-721878000", "type": "book_section", "title": "Robustness Guarantees for Structured Model Reduction of Dynamical Systems", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Pandey", "given_name": "Ayush", "orcid": "0000-0003-3590-4459", "clpid": "Pandey-Ayush" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Model reduction methods usually focus on the error performance analysis; however, in presence of uncertainties, it is important to analyze the robustness properties of the error in model reduction as well. In this paper, we give robustness guarantees for structured model reduction of linear and nonlinear dynamical systems under parametric uncertainties. In particular, we consider a model reduction where the states in the reduced model are a strict subset of the states of the full model, and the dynamics for all other states are collapsed to zero (similar to quasi-steady state approximation). We show two approaches to compute a robustness metric for any such model reduction \u2014 a direct linear analysis method for linear dynamics and a sensitivity analysis based approach that also works for nonlinear dynamics. We also prove that for linear systems, both methods give equivalent results.", "doi": "10.1109/cdc45484.2021.9683298", "isbn": "978-1-6654-3659-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-12-14", "pages": "6920-6927" }, { "id": "authors:1e54n-qhj51", "collection": "authors", "collection_id": "1e54n-qhj51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210511-085123358", "type": "book_section", "title": "Time-Optimal Navigation in Uncertain Environments with High-Level Specifications", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Rosolia", "given_name": "Ugo", "orcid": "0000-0002-1682-0551", "clpid": "Rosolia-Ugo" }, { "family_name": "Ahmadi", "given_name": "Mohamadreza", "orcid": "0000-0003-1447-3012", "clpid": "Ahmadi-Mohamadreza" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" } ], "abstract": "Mixed observable Markov decision processes (MOMDPs) are a modeling framework for autonomous systems described by both fully and partially observable states. In this work, we study the problem of synthesizing a control policy for MOMDPs that minimizes the expected time to complete the control task while satisfying syntactically co-safe Linear Temporal Logic (scLTL) specifications. First, we present an exact dynamic programming update to compute the value function. Leveraging this result, we propose a point-based approximation, which allows us to compute a lower bound of the closed-loop probability of satisfying the specifications. The effectiveness of the proposed approach and comparisons with standard strategies are shown on high-fidelity navigation tasks with partially observable static obstacles.", "doi": "10.1109/CDC45484.2021.9683486", "isbn": "978-1-6654-3659-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-12-14", "pages": "4287-4294" }, { "id": "authors:z6t4a-42m57", "collection": "authors", "collection_id": "z6t4a-42m57", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-721863000", "type": "book_section", "title": "Leveraging Classification Metrics for Quantitative System-Level Analysis with Temporal Logic Specifications", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Badithela", "given_name": "Apurva", "clpid": "Badithela-Apurva" }, { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-Tichakorn" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In many autonomy applications, performance of perception algorithms is important for effective planning and control. In this paper, we introduce a framework for computing the probability of satisfaction of formal system specifications given a confusion matrix, a statistical average performance measure for multi-class classification. We define the probability of satisfaction of a linear temporal logic formula given a specific initial state of the agent and true state of the environment. Then, we present an algorithm to construct a Markov chain that represents the system behavior under the composition of the perception and control components such that the probability of the temporal logic formula computed over the Markov chain is consistent with the probability that the temporal logic formula is satisfied by our system. We illustrate this approach on a simple example of a car with pedestrian on the sidewalk environment, and compute the probability of satisfaction of safety requirements for varying parameters of the vehicle. We also illustrate how satisfaction probability changes with varied precision and recall derived from the confusion matrix. Based on our results, we identify several opportunities for future work in developing quantitative system-level analysis that incorporates perception models.", "doi": "10.1109/cdc45484.2021.9683611", "isbn": "978-1-6654-3659-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-12-14", "pages": "564-571" }, { "id": "authors:2ybkp-8xr65", "collection": "authors", "collection_id": "2ybkp-8xr65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220503-50866100", "type": "book_section", "title": "Systems Level Model of Dietary Effects on Cognition via the Microbiome-Gut-Brain Axis", "book_title": "2021 European Control Conference (ECC)", "author": [ { "family_name": "Mayalu", "given_name": "Micha\u00eblle N.", "orcid": "0000-0002-9678-0157", "clpid": "Mayalu-Micha\u00eblle-N" }, { "family_name": "Sarma", "given_name": "Anish", "orcid": "0000-0003-1261-0589", "clpid": "Sarma-Anish-A" }, { "family_name": "Xiao", "given_name": "Fangzhou", "orcid": "0000-0002-5001-5644", "clpid": "Xiao-Fangzhou" }, { "family_name": "Doyle", "given_name": "John C.", "orcid": "0000-0002-1828-2486", "clpid": "Doyle-J-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Intercommunication of the microbiome-gut-brain axis occurs through various signaling pathways including the vagus nerve, immune system, endocrine/paracrine, and bacteria-derived metabolites. But how these pathways integrate to influence cognition remains undefined. In this paper, we create a systems level mathematical framework comprised of interconnected organ-level dynamical subsystems to increase conceptual understanding of how these subsystems contribute to cognitive performance. With this framework we propose that control of hippocampal long-term potentiation (hypothesized to correlate with cognitive performance) is influenced by interorgan signaling with diet as the external control input. Specifically, diet can influence synaptic strength (LTP) homeostatic conditions necessary for learning. The proposed model provides new qualitative information about the functional relationship between diet and output cognitive performance. The results can give insight for optimization of cognitive performance via diet in experimental animal models.", "doi": "10.23919/ecc54610.2021.9655216", "isbn": "978-9-4638-4236-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-07", "pages": "312-318" }, { "id": "authors:g0sev-vq056", "collection": "authors", "collection_id": "g0sev-vq056", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191029-132616005", "type": "book_section", "title": "Contracts of Reactivity", "book_title": "2021 European Control Conference (ECC)", "author": [ { "family_name": "Phan-Minh", "given_name": "Tung", "clpid": "Phan-Minh-Tung" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We present a theory of contracts that is centered around reacting to failures and explore it from a general assume-guarantee perspective as well as from a concrete context of automated synthesis from linear temporal logic (LTL) specifications, all of which are compatible with a contract metatheory introduced by Benveniste et al. We also provide an automated procedure for synthesizing reactive assume-guarantee contracts and implementations that capture ideas such as optimality and robustness based on assume-guarantee lattices computed from antitone Galois connection fixpoints. Lastly, we provide an example of a reactive GR(1) contract and a simulation of its implementation.", "doi": "10.23919/ECC54610.2021.9654932", "isbn": "978-9-4638-4236-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-06-29", "pages": "2611-2618" }, { "id": "authors:vwgw2-b5q48", "collection": "authors", "collection_id": "vwgw2-b5q48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210511-085543440", "type": "book_section", "title": "Limits of Probabilistic Safety Guarantees when Considering Human Uncertainty", "book_title": "2021 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Cheng", "given_name": "Richard", "orcid": "0000-0001-8301-9169", "clpid": "Cheng-Richard" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" } ], "abstract": "When autonomous robots interact with humans, such as during autonomous driving, explicit safety guarantees are crucial in order to avoid potentially life-threatening accidents. Many data-driven methods have explored learning probabilistic bounds over human agents' trajectories (i.e. confidence tubes that contain trajectories with probability \u03b4), which can then be used to guarantee safety with probability 1\u2212 \u03b4. However, almost all existing works consider \u03b4 \u2265 0.001. The purpose of this paper is to argue that (1) in safety-critical applications, it is necessary to provide safety guarantees with \u03b4 < 10\u207b\u2078, and (2) current learning-based methods are illequipped to compute accurate confidence bounds at such low \u03b4. Using human driving data (from the highD dataset), as well as synthetically generated data, we show that current uncertainty models use inaccurate distributional assumptions to describe human behavior and/or require infeasible amounts of data to accurately learn confidence bounds for \u03b4 \u2264 10\u207b\u2078. These two issues result in unreliable confidence bounds, which can have dangerous implications if deployed on safety-critical systems.", "doi": "10.1109/ICRA48506.2021.9561843", "isbn": "978-1-7281-9077-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-06", "pages": "3182-3189" }, { "id": "authors:e0ys3-46y11", "collection": "authors", "collection_id": "e0ys3-46y11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210120-165231602", "type": "book_section", "title": "Constrained Risk-Averse Markov Decision Processes", "author": [ { "family_name": "Ahmadi", "given_name": "Mohamadreza", "orcid": "0000-0003-1447-3012", "clpid": "Ahmadi-Mohamadreza" }, { "family_name": "Rosolia", "given_name": "Ugo", "orcid": "0000-0002-1682-0551", "clpid": "Rosolia-Ugo" }, { "family_name": "Ingham", "given_name": "Michel D.", "orcid": "0000-0001-5893-543X", "clpid": "Ingham-Michel-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" } ], "abstract": "We consider the problem of designing policies for Markov decision processes (MDPs) with dynamic coherent risk objectives and constraints. We begin by formulating the problem in a Lagrangian framework. Under the assumption that the risk objectives and constraints can be represented by a Markov risk transition mapping, we propose an optimization-based method to synthesize Markovian policies that lower-bound the constrained risk-averse problem. We demonstrate that the formulated optimization problems are in the form of difference convex programs (DCPs) and can be solved by the disciplined convex-concave programming (DCCP) framework. We show that these results generalize linear programs for constrained MDPs with total discounted expected costs and constraints. Finally, we illustrate the effectiveness of the proposed method with numerical experiments on a rover navigation problem involving conditional-value-at-risk (CVaR) and entropic-value-at-risk (EVaR) coherent risk measures.", "doi": "10.48550/arXiv.2012.02423", "publisher": "Association for the Advancement of Artificial Intelligence", "publication_date": "2021-05-18" }, { "id": "authors:rpyy3-e3323", "collection": "authors", "collection_id": "rpyy3-e3323", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201111-093413972", "type": "book_section", "title": "Bistable State Switch Enables Ultrasensitive Feedback Control in Heterogeneous Microbial Populations", "book_title": "2021 American Control Conference (ACC)", "author": [ { "family_name": "Ren", "given_name": "Xinying", "clpid": "Ren-Xinying" }, { "family_name": "Cuba Samaniego", "given_name": "Christian", "orcid": "0000-0003-1858-2259", "clpid": "Cuba-Samaniego-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-Elisa" } ], "abstract": "Molecular feedback control circuits can improve robustness of gene expression at single cell-level. This achievement can be offset by requirements of rapid protein expression, that may induce cellular stress, known as burden, that reduces colony growth. To begin to address this challenge we take inspiration by 'division-of-labor' in heterogeneous cell populations: we propose to combine bistable switches and quorum sensing systems to coordinate gene expression at population-level. We show that bistable switches in individual cells operating in parallel yield an ultrasensitive response, while cells maintain heterogeneous levels of gene expression. Within a feedback loop, these switches can achieve robust reference tracking and adaptation to disturbances at the population-level. We also demonstrate that molecular sequestration enables tunable hysteresis in individual switches, making it possible to obtain a wide range of stable population-level expressions.", "doi": "10.23919/ACC50511.2021.9482836", "isbn": "978-1-6654-4197-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-05", "pages": "652-659" }, { "id": "authors:dag9k-gv551", "collection": "authors", "collection_id": "dag9k-gv551", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200527-124225030", "type": "book_section", "title": "Formal Test Synthesis for Safety-Critical Autonomous Systems based on Control Barrier Functions", "book_title": "2020 59th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Akella", "given_name": "Prithvi", "clpid": "Akella-Prithvi" }, { "family_name": "Ahmadi", "given_name": "Mohamadreza", "orcid": "0000-0003-1447-3012", "clpid": "Ahmadi-Mohamadreza" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" } ], "abstract": "The prolific rise in autonomous systems has led to questions regarding their safe instantiation in real-world scenarios. Failures in safety-critical contexts such as humanrobot interactions or even autonomous driving can ultimately lead to loss of life. In this context, this paper aims to provide a method by which one can algorithmically test and evaluate an autonomous system. Given a black-box autonomous system with some operational specifications, we construct a minimax problem based on control barrier functions to generate a family of test parameters designed to optimally evaluate whether the system can satisfy the specifications. To illustrate our results, we utilize the Robotarium as a case study for an autonomous system that claims to satisfy waypoint navigation and obstacle avoidance simultaneously. We demonstrate that the proposed test synthesis framework systematically finds those sequences of events (tests) that identify points of system failure.", "doi": "10.1109/CDC42340.2020.9303776", "isbn": "9781728174471", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2020-12", "pages": "790-795" }, { "id": "authors:jz8ya-psz53", "collection": "authors", "collection_id": "jz8ya-psz53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200108-154918519", "type": "book_section", "title": "Learning Pose Estimation for UAV Autonomous Navigation and Landing Using Visual-Inertial Sensor Data", "book_title": "2020 American Control Conference (ACC)", "author": [ { "family_name": "Baldini", "given_name": "Francesca", "clpid": "Baldini-F" }, { "family_name": "Anandkumar", "given_name": "Animashree", "clpid": "Anandkumar-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this work, we propose a robust network-in-the-loop control system for autonomous navigation and landing of an Unmanned-Aerial-Vehicle (UAV). To estimate the UAV's absolute pose, we develop a deep neural network (DNN) architecture for visual-inertial odometry, which provides a robust alternative to traditional methods. We first evaluate the accuracy of the estimation by comparing the prediction of our model to traditional visual-inertial approaches on the publicly available EuRoC MAV dataset. The results indicate a clear improvement in the accuracy of the pose estimation up to 25% over the baseline. Finally, we integrate the data-driven estimator in the closed-loop flight control system of Airsim, a simulator available as a plugin for Unreal Engine, and we provide simulation results for autonomous navigation and landing.", "doi": "10.23919/ACC45564.2020.9147400", "isbn": "9781538682661", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2020-07", "pages": "2961-2966" }, { "id": "authors:rhwh9-tfa81", "collection": "authors", "collection_id": "rhwh9-tfa81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200730-143943975", "type": "book_section", "title": "Invariant Sets for Integrators and Quadrotor Obstacle Avoidance", "book_title": "2020 American Control Conference (ACC)", "author": [ { "family_name": "Doeser", "given_name": "Ludvig", "clpid": "Doeser-Ludvig" }, { "family_name": "Nilsson", "given_name": "Petter", "orcid": "0000-0001-8748-6936", "clpid": "Nilsson-Petter" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Ensuring safety through set invariance has proven a useful method in a variety of applications in robotics and control. However, finding analytical expressions for maximal invariant sets, so as to maximize the operational freedom of the system without compromising safety, is notoriously difficult for high-dimensional systems with input constraints. Here we present a generic method for characterizing invariant sets of nth-order integrator systems, based on analyzing roots of univariate polynomials. Additionally, we obtain analytical expressions for the orders n \u2264 4. Using differential flatness we subsequently leverage the results for the n = 4 case to the problem of obstacle avoidance for quadrotor UAVs. The resulting controller has a light computational footprint that showcases the power of finding analytical expressions for control-invariant sets.", "doi": "10.23919/acc45564.2020.9147872", "isbn": "9781538682661", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2020-07", "pages": "3814-3821" }, { "id": "authors:9kqpk-fqn13", "collection": "authors", "collection_id": "9kqpk-fqn13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200109-092433424", "type": "book_section", "title": "Risk-Averse Planning Under Uncertainty", "book_title": "2020 American Control Conference (ACC)", "author": [ { "family_name": "Ahmadi", "given_name": "Mohamadreza", "orcid": "0000-0003-1447-3012", "clpid": "Ahmadi-Mohamadreza" }, { "family_name": "Ono", "given_name": "Masahiro", "clpid": "Ono-Masahiro" }, { "family_name": "Ingham", "given_name": "Michel D.", "clpid": "Ingham-M-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" } ], "abstract": "We consider the problem of designing policies for partially observable Markov decision processes (POMDPs) with dynamic coherent risk objectives. Synthesizing risk-averse optimal policies for POMDPs requires infinite memory and thus undecidable. To overcome this difficulty, we propose a method based on bounded policy iteration for designing stochastic but finite state (memory) controllers, which takes advantage of standard convex optimization methods. Given a memory budget and optimality criterion, the proposed method modifies the stochastic finite state controller leading to sub-optimal solutions with lower coherent risk.", "doi": "10.23919/ACC45564.2020.9147792", "isbn": "9781538682661", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2020-07", "pages": "3305-3312" }, { "id": "authors:a835q-xhq33", "collection": "authors", "collection_id": "a835q-xhq33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200109-092058249", "type": "book_section", "title": "Intermittent Connectivity for Exploration in Communication-Constrained Multi-Agent Systems", "author": [ { "family_name": "Klaesson", "given_name": "Filip", "clpid": "Klaesson-Filip" }, { "family_name": "Nilsson", "given_name": "Petter", "orcid": "0000-0001-8748-6936", "clpid": "Nilsson-Petter" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Motivated by exploration of communication-constrained underground environments using robot teams, we study the problem of planning for intermittent connectivity in multi-agent systems. We propose a novel concept of information-consistency to handle situations where the plan is not initially known by all agents, and suggest an integer linear program for synthesizing information-consistent plans that also achieve auxiliary goals. Furthermore, inspired by network flow problems we propose a novel way to pose connectivity constraints that scales much better than previous methods. In the second part of the paper we apply these results in an exploration setting, and propose a clustering method that separates a large exploration problem into smaller problems that can be solved independently. We demonstrate how the resulting exploration algorithm is able to coordinate a team of ten agents to explore a large environment.", "doi": "10.1109/ICCPS48487.2020.00031", "publisher": "IEEE", "publication_date": "2020-04" }, { "id": "authors:dqnwk-2x543", "collection": "authors", "collection_id": "dqnwk-2x543", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200109-092918089", "type": "book_section", "title": "Towards Assume-Guarantee Profiles for Autonomous Vehicles", "book_title": "2019 IEEE 58th Conference on Decision and Control (CDC)", "author": [ { "family_name": "Phan-Minh", "given_name": "Tung", "clpid": "Phan-Minh-Tung" }, { "family_name": "Cai", "given_name": "Karena X.", "clpid": "Cai-Karena-X" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Rules or specifications for autonomous vehicles are currently formulated on a case-by-case basis, and put together in a rather ad-hoc fashion. As a step towards eliminating this practice, we propose a systematic procedure for generating a set of supervisory specifications for self-driving cars that are 1) associated with a distributed assume-guarantee structure and 2) characterizable by the notion of consistency and completeness. Besides helping autonomous vehicles make better decisions on the road, the assume-guarantee contract structure also helps address the notion of blame when undesirable events occur. We give several game-theoretic examples to demonstrate applicability of our framework.", "doi": "10.1109/CDC40024.2019.9030068", "isbn": "978-1-7281-1398-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-12", "pages": "2788-2795" }, { "id": "authors:mcspr-cxm03", "collection": "authors", "collection_id": "mcspr-cxm03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171102-092833279", "type": "book_section", "title": "Parallelizing Synthesis from Temporal Logic Specifications by Identifying Equicontrollable States", "book_title": "Robotics Research: The 18th International Symposium ISRR", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Filippidis", "given_name": "Ioannis", "orcid": "0000-0003-4704-3334", "clpid": "Filippidis-I" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Amato", "given_name": "Nancy M.", "clpid": "Amato-N-M" }, { "family_name": "Hager", "given_name": "Greg", "clpid": "Hager-G" }, { "family_name": "Thomas", "given_name": "Shawna", "clpid": "Thomas-S" }, { "family_name": "Torres-Torriti", "given_name": "Miguel", "clpid": "Torres-Torriti-M" } ], "abstract": "For the synthesis of correct-by-construction control policies from temporal logic specifications the scalability of the synthesis algorithms is often a bottleneck. In this paper, we parallelize synthesis from specifications in the GR(1) fragment of linear temporal logic by introducing a hierarchical procedure that allows decoupling of the fixpoint computations. The state space is partitioned into equicontrollable sets using solutions to parametrized games that arise from decomposing the original GR(1) game into smaller reachability-persistence games. Following the partitioning, another synthesis problem is formulated for composing the strategies from the decomposed reachability games. The formulation guarantees that composing the synthesized controllers ensures satisfaction of the given GR(1) property. Experiments with robot planning problems demonstrate good performance of the approach.", "doi": "10.1007/978-3-030-28619-4_57", "isbn": "978-3-030-28618-7", "publisher": "Springer", "place_of_publication": "Cham", "publication_date": "2019-11-28", "pages": "827-842" }, { "id": "authors:9es63-xhk04", "collection": "authors", "collection_id": "9es63-xhk04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190426-090024789", "type": "book_section", "title": "Robust Estimation Framework with Semantic Measurements", "book_title": "2019 American Control Conference (ACC)", "author": [ { "family_name": "Cai", "given_name": "Karena X.", "clpid": "Cai-Karena-X" }, { "family_name": "Harvard", "given_name": "Alexei", "clpid": "Harvard-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Chung", "given_name": "Soon-Jo", "orcid": "0000-0002-6657-3907", "clpid": "Chung-Soon-Jo" } ], "abstract": "Conventional simultaneous localization and mapping (SLAM) algorithms rely on geometric measurements and require loop-closure detections to correct for drift accumulated over a vehicle trajectory. Semantic measurements can add measurement redundancy and provide an alternative form of loop closure. We propose two different estimation algorithms that incorporate semantic measurements provided by vision-based object classifiers. An a priori map of regions where the objects can be detected is assumed. The first estimation framework is posed as a maximum-likelihood problem, where the likelihood function for semantic measurements is derived from the confusion matrices of the object classifiers. The second estimation framework is comprised of two parts: 1) a continuous-state estimation formulation that includes semantic measurements as a form of state constraints and 2) a discrete-state estimation formulation used to compute the certainty of object detection measurements using a Hidden Markov Model (HMM). The advantages of incorporating semantic measurements in these frameworks are demonstrated in numerical simulations. In particular, the proposed estimation algorithms improve upon the robustness and accuracy of conventional SLAM algorithms.", "doi": "10.23919/ACC.2019.8814793", "isbn": "978-1-5386-7926-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-07", "pages": "3809-3816" }, { "id": "authors:2bnkm-7vf48", "collection": "authors", "collection_id": "2bnkm-7vf48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190905-153443641", "type": "book_section", "title": "Transforming Data Across Environments Despite Structural Non-Identifiability", "book_title": "2019 American Control Conference (ACC)", "author": [ { "family_name": "Singhal", "given_name": "Vipul", "clpid": "Singhal-V" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The phenomenon of parameter (structural) non-identifiability can pose significant challenges to the use of parametrized dynamical models. We demonstrate that, for the case of models being used to transform data across environments, it is possible to derive conditions under which the presence of structural non-identifiability does not hinder our modeling objective. We also show that when the non-identifiability has a certain structural feature called (thin) covariation, these conditions are violated, and the transformation methodology must be modified. We demonstrate these results on the problem of correcting batch effects in cell extracts, which are used as rapid prototyping platforms in synthetic biology.", "isbn": "978-1-5386-7926-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-07", "pages": "5639-5646" }, { "id": "authors:evm0n-ds358", "collection": "authors", "collection_id": "evm0n-ds358", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190905-144348506", "type": "book_section", "title": "A modal interface contract theory for guarded input/output automata with an application in traffic system design", "book_title": "2019 American Control Conference (ACC)", "author": [ { "family_name": "Phan-Minh", "given_name": "Tung", "clpid": "Phan-Minh-Tung" }, { "family_name": "Guo", "given_name": "Steve", "clpid": "Guo-Steve" }, { "family_name": "Sch\u00fcrmann", "given_name": "Bastian", "clpid": "Sch\u00fcrmann-B" }, { "family_name": "Althoff", "given_name": "Matthias", "clpid": "Althoff-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "As a direct contribution to recent efforts of bringing formal design-by-contract methods to hybrid systems, we introduce a variant of modal interface contract theory based on input/output automata with guarded transitions. We present an algebra of operators for interface composition, contract composition, contract conjunction, contract refinement and some theorems to demonstrate that our contract object has reasonably universal semantics. As an application, we use our framework to aid the design of a networked control system of traffic.", "isbn": "978-1-5386-7926-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-07", "pages": "1704-1711" }, { "id": "authors:b9r4t-mh539", "collection": "authors", "collection_id": "b9r4t-mh539", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190905-152940342", "type": "book_section", "title": "Risk-aware motion planning for automated vehicle among human-driven cars", "book_title": "2019 American Control Conference (ACC)", "author": [ { "family_name": "Ge", "given_name": "Jin I.", "orcid": "0000-0001-6429-9337", "clpid": "Ge-Jin-I" }, { "family_name": "Sch\u00fcrmann", "given_name": "Bastian", "clpid": "Sch\u00fcrmann-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Althoff", "given_name": "Matthias", "clpid": "Althoff-M" } ], "abstract": "We consider the maneuver planning problem for automated vehicles when they share the road with human-driven cars and interact with each other using a finite set of maneuvers. Each maneuver is calculated considering input constraints, actuator disturbances and sensor noise, so that we can use a maneuver automaton to perform higher-level planning that is robust against lower-level effects. In order to model the behavior of human-driven cars in response to the intent of the automated vehicle, we use control improvisation to build a probabilistic model. To accommodate for potential mismatches between the learned human model and human driving behaviors, we use a conditional value-at-risk objective function to obtain the optimal policy for the automated vehicle. We demonstrate through simulations that our motion planning framework consisting of an interactive human driving model and risk-aware motion planning strategy makes it possible to adapt to different traffic conditions and confidence levels.", "isbn": "978-1-5386-7926-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-07", "pages": "3987-3993" }, { "id": "authors:3fjyz-v0n76", "collection": "authors", "collection_id": "3fjyz-v0n76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190822-160825121", "type": "book_section", "title": "Model of Paradoxical Signaling Regulated T-Cell Population Control for Design of Synthetic Circuits", "book_title": "2019 18th European Control Conference (ECC)", "author": [ { "family_name": "Mayalu", "given_name": "Micha\u00eblle N.", "orcid": "0000-0002-9678-0157", "clpid": "Mayalu-M-N" }, { "family_name": "Mehta", "given_name": "Harman", "clpid": "Mehta-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Paradoxical signaling occurs when the same signaling molecule can trigger antagonistic cell functions. For example, T-Cells secret cytokine IL-2 which promotes T-Cell proliferation and also affects cell death. It has been shown that cells with this signaling capability have bi-stable population dynamics. Cells can achieve identical levels of population homeostasis for initial cell concentrations within the region of attraction. These capabilities are desirable in the context of synthetic population control circuits designed for application in therapeutic treatment of various diseases. It thus becomes important to understand the dependence of the cell system on the intracellular paradoxical components and to develop accurate models to provide insight into optimal design characteristics. Here, we create a model that integrates three IL-2 driven intracellular mechanisms that trigger 1) T-cell proliferation 2) T-cell apoptosis and 3) IL-2 production. Using this model, we are able to explore the internal mechanisms necessary for paradoxical signaling in T-Cells. It was shown that the intracellular mechanisms considered were sufficient to produce population dynamic characteristics of paradoxical signaling consistent with published systems level models and data. Furthermore, analysis of parameters revealed dependency of population bistability on the production and activation of the specific intracellular proteins considered.", "doi": "10.23919/ECC.2019.8795764", "isbn": "978-3-907144-00-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-06", "pages": "2152-2158" }, { "id": "authors:jkcy4-68505", "collection": "authors", "collection_id": "jkcy4-68505", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181128-093526570", "type": "book_section", "title": "Cooperation Enhances Robustness of Coexistence in Spatially Structured Consortia", "book_title": "2019 18th European Control Conference (ECC)", "author": [ { "family_name": "Ren", "given_name": "Xinying", "clpid": "Ren-Xinying" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Designing synthetic microbial consortia is an emerging area in synthetic biology and a major goal is to realize stable and robust coexistence of multiple species. Cooperation and competition are fundamental intra/interspecies interactions that shape population level behaviors, yet it is not well-understood how these interactions affect the stability and robustness of coexistence. In this paper, we show that communities with cooperative interactions are more robust to population disturbance, e.g., depletion by antibiotics, by forming intermixed spatial patterns. Meanwhile, competition leads to population spatial heterogeneity and more fragile coexistence in communities. Using reaction-diffusion and nonlocal PDE models and simulations of a two-species E. coli consortium, we demonstrate that cooperation is more beneficial than competition in maintaining coexistence in spatially structured consortia, but not in well-mixed environments. This also suggests a tradeoff between constructing heterogeneous communities with localized functions and maintaining robust coexistence. The results provide general strategies for engineering spatially structured consortia by designing interspecies interactions and suggest the importance of cooperation for biodiversity in microbial community.", "doi": "10.23919/ECC.2019.8796069", "isbn": "978-3-907144-00-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2019-06", "pages": "2651-2656" }, { "id": "authors:ntk3d-5e996", "collection": "authors", "collection_id": "ntk3d-5e996", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191003-134611922", "type": "book_section", "title": "Inverse Abstraction of Neural Networks Using Symbolic Interpolation", "book_title": "Proceedings of the Thirty-Third AAAI Conference on Artificial Intelligence", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Gao", "given_name": "Sicun", "clpid": "Gao-Sicun" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Neural networks in real-world applications have to satisfy critical properties such as safety and reliability. The analysis of such properties typically requires extracting information through computing pre-images of the network transformations, but it is well-known that explicit computation of pre-images is intractable. We introduce new methods for computing compact symbolic abstractions of pre-images by computing their overapproximations and underapproximations through all layers. The abstraction of pre-images enables formal analysis and knowledge extraction without affecting standard learning algorithms. We use inverse abstractions to automatically extract simple control laws and compact representations for pre-images corresponding to unsafe outputs. We illustrate that the extracted abstractions are interpretable and can be used for analyzing complex properties.", "doi": "10.1609/aaai.v33i01.33013437", "isbn": "978-1-57735-809-1", "publisher": "Association for the Advancement of Artificial Intelligence (AAAI)", "publication_date": "2019-02", "pages": "3437-3444" }, { "id": "authors:ccfjf-a4206", "collection": "authors", "collection_id": "ccfjf-a4206", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180927-114224927", "type": "book_section", "title": "Role of interaction network topology in controlling microbial population in consortia", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Ren", "given_name": "Xinying", "clpid": "Ren-Xinying" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Engineering microbial consortia is an important new frontier for synthetic biology given its efficiency in performing complex tasks and endurance to environmental uncertainty. Most synthetic circuits regulate populational behaviors via cell-to-cell interactions, which are affected by spatially heterogeneous environments. Therefore, it is important to understand the limits on controlling system dynamics and provide a control strategy for engineering consortia under spatial structures. Here, we build a network model for a fractional population control circuit in two-strain consortia, and characterize the cell-to-cell interaction network by topological properties, such as symmetry, locality and connectivity. Using linear network control theory, we relate the network topology to system output's tracking performance. We analytically and numerically demonstrate that the minimum network control cost for good tracking depends on locality difference between two cell population's spatial distributions and how strongly the controller node contributes to interaction strength. To realize a robust consortia, we can manipulate the environment to form a strongly connected network. Our results ground the expected cell population dynamics in its spatially organized interaction network, and inspire directions in cooperative control in microbial consortia.", "doi": "10.1109/CDC.2018.8619704", "isbn": "978-1-5386-1395-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2018-12", "pages": "2691-2697" }, { "id": "authors:7pf29-rcc17", "collection": "authors", "collection_id": "7pf29-rcc17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190204-130950357", "type": "book_section", "title": "Optimal Experiment Design and Leveraging Competition for Shared Resources in Cell-Free Extracts", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Halter", "given_name": "Wolfgang", "clpid": "Halter-W" }, { "family_name": "Allg\u00f6wer", "given_name": "Frank", "clpid": "Allg\u00f6wer-F" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Gyorgy", "given_name": "Andras", "clpid": "Gyorgy-A" } ], "abstract": "The fact that genes compete for shared cellular resources poses a fundamental challenge when identifying parameters of genetic parts. A recently developed model of gene expression tackles this problem by explicitly accounting for resource competition. In addition to accurately describing experimental data, this model only depends on a small number of easily identifiable parameters with clear physical interpretation. Based on this model, we outline a procedure to select the optimal set of experiments to characterize biomolecular parts in synthetic biology. Additionally, we reveal the role competition for shared resources plays, provide guidelines how to minimize its detrimental effects, and how to leverage this phenomenon to extract the most information about unknown parameters. To illustrate the results, we consider the case of part characterization in cell-free extracts, treat plasmid DNA concentrations as decision variables, and demonstrate the significant performance difference between naive and optimal experiment design.", "doi": "10.1109/CDC.2018.8619039", "isbn": "978-1-5386-1395-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2018-12", "pages": "1872-1879" }, { "id": "authors:6ac4p-zrt74", "collection": "authors", "collection_id": "6ac4p-zrt74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190201-143228935", "type": "book_section", "title": "Voluntary lane-change policy synthesis with control improvisation", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Ge", "given_name": "Jin I.", "orcid": "0000-0001-6429-9337", "clpid": "Ge-Jin-I" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we use control improvisation to synthesize voluntary lane-change policy that meets human preferences under given traffic environments. We first train Markov models to describe traffic patterns and the motion of vehicles responding to such patterns using traffic data. The trained parameters are calibrated using control improvisation to ensure the traffic scenario assumptions are satisfied. Based on the traffic pattern, vehicle response models, and Bayesian switching rules, the lane-change environment for an automated vehicle is modeled as a Markov decision process. Based on human lane-change behaviors, we train a voluntary lane-change policy using explicit-duration Markov decision process. Parameters in the lane-change policy are calibrated through control improvisation to allow an automated car to pursue faster speed while maintaining desired frequency of lane-change maneuvers in various traffic environments.", "doi": "10.1109/cdc.2018.8619616", "isbn": "9781538613955", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2018-12", "pages": "3640-3647" }, { "id": "authors:mwyq5-kby06", "collection": "authors", "collection_id": "mwyq5-kby06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200131-093149145", "type": "book_section", "title": "Toward Specification-Guided Active Mars Exploration for Cooperative Robot Teams", "book_title": "Robotics: Science and Systems XIV", "author": [ { "family_name": "Nilsson", "given_name": "Petter", "orcid": "0000-0001-8748-6936", "clpid": "Nilsson-Petter" }, { "family_name": "Haesaert", "given_name": "Sofie", "clpid": "Haesaert-Sofie" }, { "family_name": "Thakker", "given_name": "Rohan", "clpid": "Thakker-Rohan-A" }, { "family_name": "Otsu", "given_name": "Kyohei", "clpid": "Otsu-Kyohei" }, { "family_name": "Vasile", "given_name": "Cristian-Ioan", "clpid": "Vasile-C-I" }, { "family_name": "Agha-Mohammadi", "given_name": "Ali-Akbar", "orcid": "0000-0001-5509-1841", "clpid": "Agha-Mohammadi-A-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ames", "given_name": "Aaron D.", "orcid": "0000-0003-0848-3177", "clpid": "Ames-A-D" } ], "contributor": [ { "family_name": "Yu", "given_name": "Tianhe", "clpid": "Yu-Tianhe" }, { "family_name": "Finn", "given_name": "Chelsea", "clpid": "Finn-C" }, { "family_name": "Dasari", "given_name": "Sudeep", "clpid": "Dasari-S" }, { "family_name": "Xie", "given_name": "Annie", "clpid": "Xie-Annie" }, { "family_name": "Zhang", "given_name": "Tianhao", "clpid": "Zhang-Tianhao" } ], "abstract": "As a step towards achieving autonomy in space exploration missions, we consider a cooperative robotics system consisting of a copter and a rover. The goal of the copter is to explore an unknown environment so as to maximize knowledge about a science mission expressed in linear temporal logic that is to be executed by the rover. We model environmental uncertainty as a belief space Markov decision process and formulate the problem as a two-step stochastic dynamic program that we solve in a way that leverages the decomposed nature of the overall system. We demonstrate in simulations that the robot team makes intelligent decisions in the face of uncertainty.", "doi": "10.15607/rss.2018.xiv.047", "isbn": "978-0-9923747-4-7", "publisher": "Robotics: Science and Systems Foundation", "publication_date": "2018-06", "pages": "1-9" }, { "id": "authors:vkhn5-n9753", "collection": "authors", "collection_id": "vkhn5-n9753", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180706-104554837", "type": "book_section", "title": "Progress towards flight software hybrid controllers from formal specifications", "book_title": "2018 IEEE Aerospace Conference", "author": [ { "family_name": "Haesaert", "given_name": "S.", "clpid": "Haesaert-S" }, { "family_name": "Reder", "given_name": "L. J.", "clpid": "Reder-L-J" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The manual translation of informally defined requirements into statecharts, from which source code can be generated automatically, can be an error-prone, laborintensive process. Design errors sometimes propagate into final implementation code, only to be discovered during testing and verification. However, the requirements that the software needs to satisfy can be formally defined via temporal logics. In this paper, an approach to automatically synthesize flight-software hybrid-controllers for dynamic systems from formal specifications is given. First, specifications for a specific control functionality are defined by a set of linear temporal logic formulas. These, together with a model of the dynamical system, are then used as inputs to the Caltech-developed temporal logic planning toolbox (TuLiP), which searches for a control design. This results in a controller that is hybrid as it combines a finite state controller together with low-level continuous control actions. We map the resulting controller design to UML statecharts, which can be given as input to the Statechart Autocoder (SCA) developed by the Jet Propulsion Laboratory. SCA maps statechart controller designs to software implementation C code suitable for flight applications. By construction, the resulting code will meet the original formal design specifications, thus eliminating latent design errors. This paper describes the new 2nd generation interface developed to specify and convert the TuLiP-produced design to more optimized (e.g., reduced number of states and transitions) input UML (as XML file) for the JPL Statechart Autocoder. By applying intermediate optimization procedures, in which indistinguishable states are merged and transitions are grouped, the size of the statechart and the resulting code is reduced substantially. This is demonstrated by revisiting our 2016 speed-controller example showing reduction by more than 75% of the states synthesized in the original example.", "doi": "10.1109/AERO.2018.8396562", "isbn": "978-1-5386-2014-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2018-03", "pages": "1-17" }, { "id": "authors:cbz07-b2614", "collection": "authors", "collection_id": "cbz07-b2614", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170920-152025463", "type": "book_section", "title": "Decomposing GR(1) Games with Singleton Liveness Guarantees for Efficient Synthesis", "book_title": "2017 IEEE 56th Annual Conference on Decision and Control (CDC)", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Temporal logic based synthesis approaches are often used to find trajectories that are correct-by-construction for systems with complex behavior. However, the scalability of such approaches is of concern and at times a bottleneck when transitioning from theory to practice. In this paper, we identify a class of problems in the GR(1) fragment of linear-time temporal logic (LTL) where the synthesis problem allows for a decomposition that enables easy parallelization. This decomposition also reduces the alternation depth, resulting in more efficient synthesis. A multi-agent robot gridworld example with coordination tasks is presented to demonstrate the application of the developed ideas and also to perform empirical analysis for benchmarking the decomposition-based synthesis approach.", "doi": "10.1109/CDC.2017.8263775", "isbn": "978-1-5090-2873-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2017-12", "pages": "911-917" }, { "id": "authors:0j175-tv586", "collection": "authors", "collection_id": "0j175-tv586", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170925-083417843", "type": "book_section", "title": "Population regulation in microbial consortia using dual feedback control", "book_title": "2017 IEEE 56th Annual Conference on Decision and Control (CDC)", "author": [ { "family_name": "Ren", "given_name": "Xinying", "clpid": "Ren-Xinying" }, { "family_name": "Baetica", "given_name": "Ania-Ariadna", "orcid": "0000-0003-0421-8181", "clpid": "Baetica-A-A" }, { "family_name": "Swaminathan", "given_name": "Anandh", "orcid": "0000-0001-9935-6530", "clpid": "Swaminathan-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "An ongoing area of study in synthetic biology has been the design and construction of synthetic circuits that maintain homeostasis at the population level. Here, we are interested in designing a synthetic control circuit that regulates the total cell population and the relative ratio between cell strains in a culture containing two different cell strains. We have developed a dual feedback control strategy that uses two separate control loops to achieve the two functions respectively. By combining both of these control loops, we have created a population regulation circuit where both the total population size and relative cell type ratio can be set by reference signals. The dynamics of the regulation circuit show robustness and adaptation to perturbations in cell growth rate and changes in cell numbers. The control architecture is general and could apply to any organism for which synthetic biology tools for quorum sensing, comparison between outputs, and growth control are available.", "doi": "10.1101/120253", "isbn": "978-1-5090-2874-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2017-12", "pages": "5341-5347" }, { "id": "authors:7abpr-0jb96", "collection": "authors", "collection_id": "7abpr-0jb96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180119-083614257", "type": "book_section", "title": "Synthesis of correct-by-construction behavior trees", "book_title": "2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", "author": [ { "family_name": "Colledanchise", "given_name": "Michele", "clpid": "Colledanchise-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "\u00d6gren", "given_name": "Petter", "clpid": "\u00d6gren-P" } ], "abstract": "In this paper we study the problem of synthesizing correct-by-construction Behavior Trees (BTs) controlling agents in adversarial environments. The proposed approach combines the modularity and reactivity of BTs with the formal guarantees of Linear Temporal Logic (LTL) methods. Given a set of admissible environment specifications, an agent model in form of a Finite Transition System and the desired task in form of an LTL formula, we synthesize a BT in polynomial time, that is guaranteed to correctly execute the desired task. To illustrate the approach, we present three examples of increasing complexity.", "doi": "10.1109/IROS.2017.8206502", "isbn": "978-1-5386-2683-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2017-09", "pages": "6039-6046" }, { "id": "authors:vrenc-fe819", "collection": "authors", "collection_id": "vrenc-fe819", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170523-230106516", "type": "book_section", "title": "Learning-Based Abstractions for Nonlinear Constraint Solving", "book_title": "Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Ar\u00e9chiga", "given_name": "Nikos", "clpid": "Ar\u00e9chiga-N" }, { "family_name": "Gao", "given_name": "Sicun", "clpid": "Gao-Sicun" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Sierra", "given_name": "Carles", "clpid": "Sierra-C" } ], "abstract": "We propose a new abstraction refinement procedure based on machine learning to improve the performance of nonlinear constraint solving algorithms on large-scale problems. The proposed approach decomposes the original set of constraints into smaller subsets, and uses learning algorithms to propose sequences of abstractions that take the form of conjunctions of classifiers. The core procedure is a refinement loop that keeps improving the learned results based on counterexamples that are obtained from partial constraints that are easy to solve. Experiments show that the proposed techniques significantly improved the performance of state-of-the-art constraint solvers on many challenging benchmarks. The mechanism is capable of producing intermediate symbolic abstractions that are also important for many applications and for understanding the internal structures of hard constraint solving problems.", "doi": "10.24963/ijcai.2017/83", "isbn": "978-0-9992411-0-3", "publisher": "International Joint Conferences on Artificial Intelligence", "publication_date": "2017-08-20", "pages": "592-599" }, { "id": "authors:2vkpx-r9522", "collection": "authors", "collection_id": "2vkpx-r9522", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170705-152213138", "type": "book_section", "title": "A fast motion planning representation for configuration flat robots with applications to micro air vehicles", "book_title": "2017 American Control Conference", "author": [ { "family_name": "Fragoso", "given_name": "Anthony T.", "orcid": "0000-0002-5805-9668", "clpid": "Fragoso-Anthony-T" }, { "family_name": "Matthies", "given_name": "Larry H.", "clpid": "Matthies-L-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Navigation of micro air vehicles (MAVs) in unknown environments is a complex sensing and trajectory generation task, particularly at high velocities. In this work, we introduce an efficient sense-and-avoid pipeline that compactly represents range measurements from multiple sensors, trajectory generation, and motion planning in a 2.5-dimensional projective data structure called an egospace representation. Egospace coordinates generalize depth image obstacle representations and are a particularly convenient choice for configuration flat mobile robots, which are differentially flat in their configuration variables and include a number of commonly used MAV plant models. After characterizing egospace obstacle avoidance for robots with trivial dynamics and establishing limits on applicability and performance, we generalize to motion planning over full configuration flat dynamics using motion primitives expressed directly in egospace coordinates. In comparison to approaches based on world coordinates, egospace uses the natural sensor geometry to combine the benefits of a multiresolution and multi-sensor representation architecture into a single simple and efficient layer.", "doi": "10.23919/ACC.2017.7963600", "isbn": "978-1-5090-5992-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2017-05", "pages": "4195-4202" }, { "id": "authors:pdj4p-zcv35", "collection": "authors", "collection_id": "pdj4p-zcv35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170705-155806564", "type": "book_section", "title": "Connected cruise control design using probabilistic model checking", "book_title": "2017 American Control Conference", "author": [ { "family_name": "Ge", "given_name": "Jin I.", "orcid": "0000-0001-6429-9337", "clpid": "Ge-Jin-I" }, { "family_name": "Orosz", "given_name": "G\u00e1bor", "orcid": "0000-0002-9000-3736", "clpid": "Orosz-G" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we synthesize a connected cruise controller with performance guarantee using probabilistic model checking, for a vehicle that receives motion information from several vehicles ahead through wireless vehicle-to-vehicle communication. We model the car-following dynamics of the preceding vehicles as Markov chains and synthesize the connected cruise controller as a Markov decision process. We show through simulations that such a design is robust against imperfections in communication.", "doi": "10.23919/ACC.2017.7963724", "isbn": "978-1-5090-5992-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2017-05", "pages": "4964-4970" }, { "id": "authors:njttn-8e877", "collection": "authors", "collection_id": "njttn-8e877", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170303-084805424", "type": "book_section", "title": "Enhancing tolerance to unexpected jumps in GR(1) games", "book_title": "Proceedings of the 8th ACM/IEEE International Conference on Cyber-Physical Systems, Pitssburgh, PA USA, April 2017 (ICCPS)", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "When used as part of a hybrid controller, finite-memory strategies synthesized from linear-time temporal logic (LTL) specifications rely on an accurate dynamics model in order to ensure correctness of trajectories. In the presence of uncertainty about the underlying model, there may exist unexpected trajectories that manifest as unexpected transitions\nunder control of the strategy. While some disturbances can be captured by augmenting the dynamics model, such approaches may be conservative in that bisimulations may fail to exist for\nwhich strategies can be synthesized. In this paper, we consider games of the GR(1) fragment of LTL, and we characterize the tolerance of hybrid controllers to perturbations that appear as unexpected jumps (transitions) to states in the discrete strategy part of the controller. \n\nAs a first step, we show robustness to certain unexpected transitions that occur in a finite manner, i.e., despite a certain number of unexpected jumps, the sequence of states obtained will still meet a stricter specification and hence the original specification. Additionally, we propose algorithms to improve robustness by increasing tolerance to additional disturbances. A robot gridworld example is presented to demonstrate the application of the developed ideas and also to perform empirical analysis.", "doi": "10.1145/3055004.3055014", "isbn": "978-1-4503-4965-9", "publisher": "ACM", "place_of_publication": "New York, NY", "publication_date": "2017-04-18", "pages": "37-47" }, { "id": "authors:57jtz-prh09", "collection": "authors", "collection_id": "57jtz-prh09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170221-080512453", "type": "book_section", "title": "Synthesis of reactive control protocols for switch electrical power systems for commercial application with safety specifications", "book_title": "2016 IEEE Symposium Series on Computational Intelligence (SSCI)", "author": [ { "family_name": "Christalin", "given_name": "Benson", "clpid": "Christalin-B" }, { "family_name": "Colledanchise", "given_name": "Michele", "clpid": "Colledanchise-M" }, { "family_name": "\u00d6gren", "given_name": "Petter", "clpid": "\u00d6gren-P" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper presents a method for the reactive synthesis of fault-tolerant optimal control protocols for a finite deterministic discrete event system subject to safety specifications. A Deterministic Finite State Machine (DFSM) and Behavior Tree (BT) were used to model the system. The synthesis procedure involves formulating the policy problem as a shortest path dynamic programming problem. The procedure evaluates all possible states when applied to the DFSM, or over all possible actions when applied to the BT. The resulting strategy minimizes the number of actions performed to meet operational objectives without violating safety conditions. The effectiveness of the procedure on DFSMs and BTs is demonstrated through three examples of switched electrical power systems for commercial application and analyzed using run-time complexity analysis. The results demonstrated that for large order system BTs provided a tractable model to synthesize an optimal control policy.", "doi": "10.1109/SSCI.2016.7849873", "isbn": "978-1-5090-4241-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-12", "pages": "1-8" }, { "id": "authors:cmfhw-jcb74", "collection": "authors", "collection_id": "cmfhw-jcb74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170111-150445053", "type": "book_section", "title": "Quantifying resource competition and its effects in the TX-TL system", "book_title": "IEEE 55th Conference on Decision and Control (CDC)", "author": [ { "family_name": "Gyorgy", "given_name": "Andras", "clpid": "Gyorgy-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Without accounting for the limited availability of shared cellular resources, the standard model of gene expression fails to reliably predict experimental data obtained in vitro. To overcome this limitation, we develop a dynamical model of gene expression explicitly modeling competition for scarce resources. In addition to accurately describing the experimental data, this model only depends on a handful of easily identifiable parameters with clear physical interpretation. Based on this model, we then characterize the combinations of protein concentrations that are simultaneously realizable with shared resources. As application examples, we demonstrate how the results can be used to explain similarities/differences among different in vitro extracts, furthermore, we illustrate that accounting for resource usage is essential in circuit design considering the toggle switch.", "doi": "10.1109/CDC.2016.7798775", "isbn": "978-1-5090-1837-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-12", "pages": "3363-3368" }, { "id": "authors:7tkhx-yd005", "collection": "authors", "collection_id": "7tkhx-yd005", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170111-134705561", "type": "book_section", "title": "Automata theory meets approximate dynamic programming: Optimal control with temporal logic constraints", "book_title": "55th Conference on Decision and Control (CDC), 2016", "author": [ { "family_name": "Papusha", "given_name": "Ivan", "clpid": "Papusha-I" }, { "family_name": "Fu", "given_name": "Jie", "clpid": "Fu-Jie" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We investigate the synthesis of optimal controllers for continuous-time and continuous-state systems under temporal logic specifications. The specification is expressed as a deterministic, finite automaton (the specification automaton) with transition costs, and the optimal system behavior is captured by a cost function that is integrated over time. We construct a dynamic programming problem over the product of the underlying continuous-time, continuous-state system and the discrete specification automaton. To solve this dynamic program, we propose controller synthesis algorithms based on approximate dynamic programming (ADP) for both linear and nonlinear systems under temporal logic constraints. We argue that ADP allows treating the synthesis problem directly, without forming expensive discrete abstractions. We show that, for linear systems under co-safe temporal logic constraints, the ADP solution reduces to a single semidefinite program.", "doi": "10.1109/CDC.2016.7798307", "isbn": "978-1-5090-1838-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-12", "pages": "434-440" }, { "id": "authors:gjwhg-3pr04", "collection": "authors", "collection_id": "gjwhg-3pr04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170111-150031011", "type": "book_section", "title": "Constrained autonomous satellite docking via differential flatness and model predictive control", "book_title": "IEEE 55th Conference on Decision and Control (CDC)", "author": [ { "family_name": "Farahani", "given_name": "Samira S.", "clpid": "Farahani-S-S" }, { "family_name": "Papusha", "given_name": "Ivan", "clpid": "Papusha-I" }, { "family_name": "McGhan", "given_name": "Catharine", "clpid": "McGhan-C-L-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We investigate trajectory generation algorithms that allow a satellite to autonomously rendezvous and dock with a target satellite to perform maintenance tasks, or transport the target satellite to a new operational location. We propose different path planning strategies for each of the phases of rendezvous. In the first phase, the satellite navigates to a point in the Line of Sight (LOS) region of the target satellite. We show that the satellite's equations of motion are differentially flat in the relative coordinates, hence the rendezvous trajectory can be found efficiently in the flat output space without a need to integrate the full nonlinear dynamics. In the second phase, we use model predictive control (MPC) with linearized dynamics to navigate the spacecraft to the final docking location within a constrained approach envelope. We demonstrate feasibility of this study by simulating a sample docking mission.", "doi": "10.1109/CDC.2016.7798766", "isbn": "978-1-5090-1837-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-12", "pages": "3306-3311" }, { "id": "authors:py6yc-hy415", "collection": "authors", "collection_id": "py6yc-hy415", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190822-074943945", "type": "book_section", "title": "Risk-aware Planning in Hybrid Domains: An Application to Autonomous Planetary Rovers", "book_title": "AIAA SPACE 2016", "author": [ { "family_name": "Santana", "given_name": "Pedro", "clpid": "Sanatan-P" }, { "family_name": "Vaquero", "given_name": "Tiago", "clpid": "Vaquero-T" }, { "family_name": "Timmons", "given_name": "Eric", "clpid": "Timmons-E" }, { "family_name": "Williams", "given_name": "Brian C.", "clpid": "Williams-B-C" }, { "family_name": "McGhan", "given_name": "Catharine L. R.", "clpid": "McGhan-C-L-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Toledo", "given_name": "Cl\u00e1udio", "clpid": "Toledo-C" } ], "abstract": "Expanding robotic space exploration beyond the immediate vicinity of Earth's orbit can only be achieved by increasingly autonomous agents, given the sometimes insurmountable challenges of teleoperation over great distances. Among the numerous requirements that a fully autonomous robotic space explorer must meet, here we focus on three key mission-enabling technologies: the ability to act under uncertainty and adapt to its environment; the ability to optimize performance while offering hard bounds on the risk of mission failure; and the ability to handle complex hybrid (discrete and continuous) mission planning problems in a provably correct and scalable fashion. In this paper, we show how CLARK, a planner capable of generating risk-bounded, dynamic temporal plans for autonomous agents operating under uncertainty, is able to efficiently generate temporal plans for a challenging planetary rover scenario featuring temporal uncertainty that could not be addressed by previous methods.", "doi": "10.2514/6.2016-5537", "isbn": "978-1-62410-427-5", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2016-09-09", "pages": "Art. No. 2016-5537" }, { "id": "authors:y50n2-rdm74", "collection": "authors", "collection_id": "y50n2-rdm74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190822-090943975", "type": "book_section", "title": "Towards Architecture-wide Analysis, Verification, and Validation for Total System Stability During Goal-Seeking Space Robotics Operations", "book_title": "AIAA SPACE 2016", "author": [ { "family_name": "McGhan", "given_name": "Catharine L. R.", "clpid": "McGhan-C-L-R" }, { "family_name": "Wang", "given_name": "Yuh-Shyang", "orcid": "0000-0001-7357-7247", "clpid": "Wang-Yuh-Shyang" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Vaquero", "given_name": "Tiago", "clpid": "Vaquero-T" }, { "family_name": "Williams", "given_name": "Brian C.", "clpid": "Williams-B-C" }, { "family_name": "Colledanchise", "given_name": "Michele", "clpid": "Colledanchise-M" }, { "family_name": "\u00d6gren", "given_name": "Petter", "clpid": "\u00d6gren-P" } ], "abstract": "In this paper we discuss the beginnings of an attempt to define and analyze the stability of an entire modular robotic system architecture - one which includes a three-tier (3T) layer breakdown of capabilities, with symbolic, deterministic planning at the highest level. We approach the problem from the standpoint of a control theory outlook, and try to formalize the issues that result from trying to quantitatively characterize the overall performance of a well-defined system without a need for exhaustive testing. We start by discussing the concept of bounded-input bounded-output stability, giving examples where the technique might not be sufficient to guarantee what we term \"total system stability\" due to complications associated with the levels of abstraction between the modules and components that are being chained together in the architecture. We then go on to discuss necessary conditions that may fall out of this naturally as a result. We further try to better-define the input and output constraints needed to guarantee total system stability, using an assumption-guarantee-like contractual framework that sits alongside the architecture; the requirements then may have influence across multiple modules, in order to keep consistency. We also discuss how the structure of the architectural modules may help or hinder the process of capability characterization and performance analysis of each module and a given architecture configuration as a whole. We then discuss two overlapping methods that, combined, should allow us to analyze the effectiveness of the architecture, and help towards verification and validation of both the components and the system as a whole. Demonstrative examples are given using a specific architectural implementation called the Resilient Spacecraft Executive. In future work, we hope to define both necessary and sufficient conditions for total system stability across such a system architecture for robotics\nuse.", "doi": "10.2514/6.2016-5607", "isbn": "978-1-62410-427-5", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2016-09-09", "pages": "Art. No. 2016-5607" }, { "id": "authors:cabp8-4rk89", "collection": "authors", "collection_id": "cabp8-4rk89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190822-084034717", "type": "book_section", "title": "Resilient Spacecraft Executive: An Architecture for Risk-Aware Operations in Uncertain Environments", "book_title": "AIAA SPACE 2016", "author": [ { "family_name": "McGhan", "given_name": "Catharine L. R.", "clpid": "McGhan-C-L-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Vaquero", "given_name": "Tiago", "clpid": "Vaquero-T" }, { "family_name": "Williams", "given_name": "Brian C.", "clpid": "Williams-B-C" }, { "family_name": "Ingham", "given_name": "Michel D.", "clpid": "Ingham-M-D" }, { "family_name": "Ono", "given_name": "Masahiro", "clpid": "Ono-Masahiro" }, { "family_name": "Estlin", "given_name": "Tara", "clpid": "Estlin-T" }, { "family_name": "Lanka", "given_name": "Ravi", "clpid": "Lanka-R" }, { "family_name": "Arslan", "given_name": "Oktay", "clpid": "Arslan-O" }, { "family_name": "Elaasar", "given_name": "Maged E.", "clpid": "Elaasar-M-E" } ], "abstract": "In this paper we discuss the latest results from the Resilient Space Systems project, a joint effort between Caltech, MIT, NASA Jet Propulsion Laboratory (JPL), and the Woods Hole Oceanographic Institution (WHOI). The goal of the project is to define a resilient, risk-aware software architecture for onboard, real-time autonomous operations that can robustly handle uncertainty in spacecraft behavior within hazardous and unconstrained environments, without unnecessarily increasing complexity. The architecture, called the Resilient Spacecraft Executive (RSE), has been designed to support three functions: (1) adapting to component failures to allow graceful degradation, (2) accommodating environments, science observations, and spacecraft capabilities that are not fully known in advance, and (3) making risk-aware decisions without waiting for slow ground-based reactions. In implementation, the bulk of the RSE effort has focused on the parts of the architecture used for goal-directed execution and control, including the deliberative, habitual, and reflexive modules. We specify the capabilities and constraints needed for each module, and discuss how we have extended the current state-of-the-art algorithms so that they can supply the required functionality, such as risk-aware planning in the deliberative module that conforms to mission operator-supplied priorities and constraints. Furthermore, the RSE architecture is modular to enable extension and reconfiguration, as long as the embedded algorithmic components exhibit the required risk-aware behavior in the deliberative module and risk-bounded behavior in the habitual module. To that end, we discuss some feasible, useful RSE configurations and deployments for a Mars rover case and an autonomous underwater vehicle case. We also discuss additional capabilities that the architecture requires to support needed resiliency, such as onboard analysis and learning.", "doi": "10.2514/6.2016-5541", "isbn": "978-1-62410-427-5", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2016-09-09", "pages": "Art. No. 2016-5541" }, { "id": "authors:2k6hk-3fd81", "collection": "authors", "collection_id": "2k6hk-3fd81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161020-140012994", "type": "book_section", "title": "Control design for hybrid systems with TuLiP: The Temporal Logic Planning toolbox", "book_title": "2016 IEEE Conference on Control Applications (CCA)", "author": [ { "family_name": "Filippidis", "given_name": "Ioannis", "orcid": "0000-0003-4704-3334", "clpid": "Filippidis-I" }, { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This tutorial describes TuLiP, the Temporal Logic Planning toolbox, a collection of tools for designing controllers for hybrid systems from specifications in temporal logic. The tools support a workflow that starts from a description of desired behavior, and of the system to be controlled. The system can have discrete state, or be a hybrid dynamical system with a mixed discrete and continuous state space. The desired behavior can be represented with temporal logic and discrete transition systems. The system description can include uncontrollable variables that take discrete or continuous values, and represent disturbances and other environmental factors that affect the dynamics, as well as communication signals that affect controller decisions.", "doi": "10.1109/CCA.2016.7587949", "isbn": "978-1-5090-0755-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-09", "pages": "1030-1041" }, { "id": "authors:fgb0j-90y51", "collection": "authors", "collection_id": "fgb0j-90y51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160801-165143151", "type": "book_section", "title": "Symbolic construction of GR(1) contracts for systems with full information", "book_title": "2016 American Control Conference (ACC)", "author": [ { "family_name": "Filippidis", "given_name": "Ioannis", "orcid": "0000-0003-4704-3334", "clpid": "Filippidis-I" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This work proposes a symbolic algorithm for the construction of assume-guarantee specifications that allow multiple agents to cooperate. Each agent is assigned goals expressed in a fragment of linear temporal logic known as generalized Streett with one pair, GR(1). These goals may be unrealizable, unless each agent makes additional assumptions, about the behavior of other agents. The algorithm constructs a contract among the agents, in that only the infinite behavior of the given goals is constrained, known as liveness, not the finite one, known as safety. This defers synthesis to a later stage of refinement, modularizing the design process. We prove that there exist GR(1) games that do not admit any refining GR(1) contract. For this reason, we formulate contracts with nested GR(1) properties and auxiliary communication variables, and prove that they always exist. The algorithm's fixpoint structure is similar to GR(1) synthesis, enjoying time complexity polynomial in the number of states, and linear in number of recurrence goals.", "doi": "10.1109/ACC.2016.7525009", "isbn": "978-1-4673-8680-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-07", "pages": "782-789" }, { "id": "authors:j3k2e-3vf46", "collection": "authors", "collection_id": "j3k2e-3vf46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170118-094026442", "type": "book_section", "title": "Robust model predictive control for an uncertain smart thermal grid", "book_title": "2016 European Control Conference (ECC)", "author": [ { "family_name": "Farahani", "given_name": "Samira S.", "clpid": "Farahani-S-S" }, { "family_name": "Lukszo", "given_name": "Zofia", "clpid": "Lukszo-Z" }, { "family_name": "Keviczky", "given_name": "Tam\u00e1s", "clpid": "Keviczky-T" }, { "family_name": "De Schutter", "given_name": "Bart", "clpid": "De-Schutter-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The focus of this paper is on modeling and control of Smart Thermal Grids (STGs) in which the uncertainties in the demand and/or supply are included. We solve the corresponding robust model predictive control (MPC) optimization problem using mixed-integer-linear programming techniques to provide a day-ahead prediction for the heat production in the grid. In an example, we compare the robust MPC approach with the robust optimal control approach, in which the day-ahead production plan is obtained by optimizing the objective function for entire day at once. There, we show that the robust MPC approach successfully keeps the supply-demand balance in the STG while satisfying the constraints of the production units in the presence of uncertainties in the heat demand. Moreover, we see that despite the longer computation time, the performance of the robust MPC controller is considerably better than the one of the robust optimal controller.", "doi": "10.1109/ECC.2016.7810452", "isbn": "978-1-5090-2591-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-07", "pages": "1195-1200" }, { "id": "authors:8fw99-47959", "collection": "authors", "collection_id": "8fw99-47959", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160802-094940806", "type": "book_section", "title": "Linear System Identifiability from Distributional and Time Series Data", "book_title": "2016 American Control Conference (ACC)", "author": [ { "family_name": "Swaminathan", "given_name": "Anandh", "orcid": "0000-0001-9935-6530", "clpid": "Swaminathan-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider identifiability of linear systems driven by white noise using a combination of distributional and time series measurements. Specifically, we assume that the system has no control inputs available and can only be observed at stationarity. The user is able to measure the full stationary state distribution as well as observe time correlations for small subsets of the state. We formulate theoretical conditions on identifiability of parameters from distributional information alone. We then give a sufficient condition and an effective necessary condition for identifiability using a combination of distributional and time series measurements. We illustrate the ideas with some simple examples as well as a biologically inspired example of a transcription and degradation process.", "doi": "10.1109/ACC.2016.7524946", "isbn": "978-1-4673-8680-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2016-07", "pages": "392-399" }, { "id": "authors:am445-nq820", "collection": "authors", "collection_id": "am445-nq820", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161116-150409481", "type": "book_section", "title": "Optimal Control of Nonlinear Systems with Temporal Logic Specifications", "book_title": "Robotics Research", "author": [ { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Inaba", "given_name": "Masayuki", "clpid": "Inaba-M" }, { "family_name": "Corke", "given_name": "Peter", "clpid": "Corke-P" } ], "abstract": "We present a mathematical programming-based method for optimal control of nonlinear systems subject to temporal logic task specifications. We specify tasks using a fragment of linear temporal logic (LTL) that allows both finite- and infinite-horizon properties to be specified, including tasks such as surveillance, periodic motion, repeated assembly, and environmental monitoring. Our method directly encodes an LTL formula as mixed-integer linear constraints on the system variables, avoiding the computationally expensive process of creating a finite abstraction. Our approach is efficient; for common tasks our formulation uses significantly fewer binary variables than related approaches and gives the tightest possible convex relaxation. We apply our method on piecewise affine systems and certain classes of differentially flat systems. In numerical experiments, we solve temporal logic motion planning tasks for high-dimensional (10+ \n+\n continuous state) systems.", "doi": "10.1007/978-3-319-28872-7_2", "isbn": "978-3-319-28870-3", "publisher": "Springer", "place_of_publication": "Cham", "publication_date": "2016-04-23", "pages": "21-37" }, { "id": "authors:s6ncb-46094", "collection": "authors", "collection_id": "s6ncb-46094", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160404-092715239", "type": "book_section", "title": "Application of Correct-by-Construction Principles for a Resilient Risk-Aware Architecture", "book_title": "AIAA SPACE 2015 Conference and Exposition", "author": [ { "family_name": "McGhan", "given_name": "Catharine L. R.", "clpid": "McGhan-C-L-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we discuss the application of correct-by-construction techniques to a resilient,\nrisk-aware software architecture for onboard, real-time autonomous operations. We\nmean to combat complexity and the accidental introduction of bugs through the use of\nverifiable auto-coding software and correct-by-construction techniques, and discuss the use\nof a toolbox for correct-by-construction Temporal Logic Planning (TuLiP) for such a purpose.\nWe describe some of TuLiP's current functionality, specifically its ability to model\nsymbolic discrete systems and synthesize software controllers and control policies that are\ncorrect-by-construction. We then move on to discuss the use of these techniques to define a\ndeliberative goal-directed executive capability that performs risk-informed action-planning\n\u2013 to satisfy the mission goals (specified by mission control) within the specified priorities\nand constraints. Finally, we discuss an application of the TuLiP process to a simple rover\nresilience scenario.", "doi": "10.2514/6.2015-4527", "isbn": "978-1-62410-334-6", "publisher": "AIAA", "place_of_publication": "Reston, VA", "publication_date": "2016-04-04" }, { "id": "authors:n2t51-awx04", "collection": "authors", "collection_id": "n2t51-awx04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160725-112209526", "type": "book_section", "title": "Interfacing TuLiP with the JPL Statechart Autocoder: Initial progress toward synthesis of flight software from formal specifications", "author": [ { "family_name": "Dathathri", "given_name": "Sumanth", "clpid": "Dathathri-S" }, { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Reder", "given_name": "Leonard J.", "clpid": "Reder-L-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes the implementation of an interface\nconnecting the two tools : the JPL SCA (Statechart\nAutocoder) and TuLiP (Temporal Logic Planning Toolbox) to\nenable the automatic synthesis of low level implementation\ncode directly from formal specifications. With system dynamics, bounds on uncertainty and formal specifications as\ninputs, TuLiP synthesizes Mealy machines that are correct-by-construction. An interface is built that automatically translates these Mealy machines into UML statecharts. The SCA accepts the UML statecharts (as XML files) to synthesize flight-certified implementation code. The functionality of the interface is demonstrated through three example systems of varying complexity\na) a simple thermostat b) a simple speed controller for\nan autonomous vehicle and c) a more complex speed controller\nfor an autonomous vehicle with a map-element. In the thermostat controller, there is a specification regarding the desired temperature range that has to be met despite disturbance from the environment. Similarly, in the speed-controllers there are specifications about safe driving speeds depending on sensor health (sensors fail unpredictably) and the map-location. The\nsignificance of these demonstrations is the potential circumventing of some of the manual design of statecharts for flight software/controllers. As a result, we expect that less testing and validation will be necessary. In applications where the products of synthesis are used alongside manually designed components, extensive testing or new certificates of correctness of the composition may still be required.", "doi": "10.1109/AERO.2016.7500557", "publisher": "IEEE", "publication_date": "2016-03" }, { "id": "authors:pktsg-xey74", "collection": "authors", "collection_id": "pktsg-xey74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-104956130", "type": "book_section", "title": "Synthesis of reactive controllers for hybrid systems (keynote)", "book_title": "Proceedings of the 43rd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages", "author": [ { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Decision-making logic in hybrid systems is responsible for selecting modes of operation for the underlying (continuous) control system, reacting to external events and failures in the system, and insuring that the overall control system is satisfying safety and performance specifications. Tools from computer science, such as model-checking and logic synthesis, combined with design patterns from feedback control theory provide new approaches to solving these problems. A major shift is the move from \"design then verify'' to \"specify then synthesize'' approaches to controller design that allow simultaneous synthesis of high-performance, robust control laws and correct-by-construction decision-making logic.", "doi": "10.1145/2837614.2843894", "isbn": "978-1-4503-3549-2", "publisher": "Association for Computing Machinery", "place_of_publication": "New York, NY", "publication_date": "2016-01", "pages": "3" }, { "id": "authors:jgasm-tg452", "collection": "authors", "collection_id": "jgasm-tg452", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160216-132738380", "type": "book_section", "title": "Analysis of Control Systems on Symmetric Cones", "book_title": "54th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Papusha", "given_name": "Ivan", "clpid": "Papusha-I" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "It is well known that exploiting special structure is a powerful way to extend the reach of current optimization tools to higher dimensions. While many linear control systems can be treated satisfactorily with linear matrix inequalities (LMI) and semidefinite programming (SDP), practical considerations can still restrict scalability of general methods. Thus, we wish to work with high dimensional systems without explicitly forming SDPs. To that end, we exploit a particular kind of structure in the dynamics matrix, paving the way for a more efficient treatment of a certain class of linear systems. We show how second order cone programming (SOCP) can be used instead of SDP to find Lyapunov functions that certify stability. This framework reduces to a famous linear program (LP) when the system is internally positive, and to a semidefinite program (SDP) when the system has no special structure.", "doi": "10.1109/CDC.2015.7402836", "isbn": "978-1-4799-7884-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-12", "pages": "3971-3976" }, { "id": "authors:rtm9d-fbz53", "collection": "authors", "collection_id": "rtm9d-fbz53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160217-085432492", "type": "book_section", "title": "A stochastic framework for the design of transient and steady state behavior of biochemical reaction networks", "book_title": "54th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Baetica", "given_name": "Ania A.", "orcid": "0000-0003-0421-8181", "clpid": "Baetica-A-A" }, { "family_name": "Yuan", "given_name": "Ye", "orcid": "0000-0001-7858-0437", "clpid": "Yuan-Ye" }, { "family_name": "Gon\u00e7alves", "given_name": "Jorge", "clpid": "Gon\u00e7alves-J-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Stochasticity plays an essential role in the dynamics of biochemical systems. Stochastic behaviors of bimodality, excitability, and fluctuations are present in biochemical reaction networks at low molecular numbers. These stochastic dynamics can be captured by modeling the system using a forward Kolmogorov equation known in the biochemical literature as the chemical master equation. The chemical master equation describes the time evolution of probability distributions of molecule species in the system. We develop a stochastic framework for the design of these time evolving probability distributions. Our design specifications include their uni-/multi-modality, the locations of their modes, and their rate of convergence to the stationary distribution. We formulate these specifications as constraints in an optimization program that determines the desired reaction rate values. We apply our design framework to examples of biochemical reaction networks to illustrate its strengths and limitations.", "doi": "10.1109/CDC.2015.7402699", "isbn": "978-1-4799-7884-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-12", "pages": "3199-3205" }, { "id": "authors:hvrf3-g6n29", "collection": "authors", "collection_id": "hvrf3-g6n29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160217-083025676", "type": "book_section", "title": "Engineering principles of synthetic biochemical oscillators with negative cyclic feedback", "book_title": "54th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Hori", "given_name": "Yutaka", "orcid": "0000-0002-3253-4985", "clpid": "Hori-Yutaka" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper analyzes oscillatory dynamics of a class of cyclic gene regulatory networks and provides engineering principles for the synthesis of biochemical oscillators. We first review previous results that the oscillatory parameter regime of the gene regulatory circuits can be rigorously explored by the local stability analysis of a unique equilibrium. The local stability analysis then leads to the first engineering principle that the circuit components, or genes, should be chosen so that the kinetic profiles of the circuit components are similar to each other. Using a homogeneous oscillator model, we further discuss design strategies to reduce the cell-to-cell variability of the oscillators that is caused by intrinsic noise.", "doi": "10.1109/CDC.2015.7402292", "isbn": "978-1-4799-7884-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-12", "pages": "584-589" }, { "id": "authors:f2kgh-jdv95", "collection": "authors", "collection_id": "f2kgh-jdv95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161208-102939866", "type": "book_section", "title": "An Iterative Abstraction Algorithm for Reactive Correct-by-Construction Controller Synthesis", "book_title": "54th IEEE Conference on Decision and Control (CDC), 2015", "author": [ { "family_name": "Mattila", "given_name": "Robert", "clpid": "Mattila-R" }, { "family_name": "Mo", "given_name": "Yilin", "orcid": "0000-0001-7937-6737", "clpid": "Mo-Yilin" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the problem of synthesizing correct-by-construction controllers for discrete-time dynamical systems. A commonly adopted approach in the literature is to abstract the dynamical system into a Finite Transition System (FTS) and thus convert the problem into a two player game between the environment and the system on the FTS. The controller design problem can then be solved using synthesis tools for general linear temporal logic or generalized reactivity(1) specifications. In this article, we propose a new abstraction algorithm. Instead of generating a single FTS to represent the system, we generate two FTSs, which are under- and over-approximations of the original dynamical system. We further develop an iterative abstraction scheme by exploiting the concept of winning sets, i.e., the sets of states for which there exists a winning strategy for the system. Finally, the efficiency of the new abstraction algorithm is illustrated by numerical examples.", "doi": "10.1109/CDC.2015.740318671", "isbn": "978-1-4799-7886-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-12", "pages": "6147-6152" }, { "id": "authors:4t6ga-7hh74", "collection": "authors", "collection_id": "4t6ga-7hh74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160412-095801286", "type": "book_section", "title": "Online Horizon Selection in Receding Horizon Temporal Logic Planning", "book_title": "2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", "author": [ { "family_name": "Raman", "given_name": "Vasumathi", "clpid": "Raman-V" }, { "family_name": "F\u00e4lt", "given_name": "Mattias", "clpid": "F\u00e4lt-M" }, { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Temporal logics have proven effective for correct-by-construction synthesis of controllers for a wide range of robotic applications. Receding horizon frameworks mitigate the computational intractability of reactive synthesis for temporal logic, but have thus far been limited by pursuing a single sequence of short horizon problems to the goal. We propose a receding horizon algorithm for reactive synthesis that automatically determines a path to the currently pursued goal at runtime, responding as needed to nondeterministic environment behavior. This is achieved by allowing each short horizon to have multiple local goals, and determining which local goal to pursue based on the current global goal, the currently perceived environment and a pre-computed invariant dependent on the global goal. We demonstrate the utility of this additional flexibility in grant-response tasks, using a search-and-rescue example. Moreover, we show that these goal-dependent invariants mitigate the conservativeness of the receding horizon approach.", "doi": "10.1109/IROS.2015.7353864", "isbn": "978-1-4799-9994-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-10", "pages": "3493-3499" }, { "id": "authors:cgc8r-zpc45", "collection": "authors", "collection_id": "cgc8r-zpc45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150915-083424809", "type": "book_section", "title": "Multi-dimensional state estimation in adversarial environment", "book_title": "34th Chinese Control Conference (CCC)", "author": [ { "family_name": "Mo", "given_name": "Yilin", "orcid": "0000-0001-7937-6737", "clpid": "Mo-Yilin" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the estimation of a vector state based on m measurements that can be potentially manipulated by an adversary. The attacker is assumed to have limited resources and can only manipulate up to l of the m measurements. However, it can the compromise measurements arbitrarily. The problem is formulated as a minimax optimization, where one seeks to construct an optimal estimator that minimizes the \"worst-case\" error against all possible manipulations by the attacker and all possible sensor noises. We show that if the system is not observable after removing 2l sensors, then the worst-case error is infinite, regardless of the estimation strategy. If the system remains observable after removing arbitrary set of 2l sensor, we prove that the optimal state estimation can be computed by solving a semidefinite programming problem. A numerical example is provided to illustrate the effectiveness of the proposed state estimator.", "doi": "10.1109/ChiCC.2015.7260376", "isbn": "978-9-8815-6389-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-07", "pages": "4761-4766" }, { "id": "authors:v5qp9-11a46", "collection": "authors", "collection_id": "v5qp9-11a46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151124-114616357", "type": "book_section", "title": "A state-space realization approach to set identification of biochemical kinetic parameters", "author": [ { "family_name": "Hori", "given_name": "Yutaka", "orcid": "0000-0002-3253-4985", "clpid": "Hori-Yutaka" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper proposes a set-based parameter identification method for biochemical systems. The developed method identifies not a single parameter but a set of parameters that all explain time-series experimental data, enabling the systematic characterization of the uncertainty of identified parameters. Our key idea is to use a state-space realization that has the same input-output behavior as experimental data instead of the experimental data itself for the identification. This allows us to relax the originally nonlinear identification problem to an LMI feasibility problem validating the norm bound of an error system. We show that regions of parameters can be efficiently classified into consistent and inconsistent parameter sets by combining the LMI feasibility problems and a generalized bisection algorithm.", "doi": "10.1109/ECC.2015.7330878", "publisher": "IEEE", "publication_date": "2015-07" }, { "id": "authors:dy79n-kgr93", "collection": "authors", "collection_id": "dy79n-kgr93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160318-094020866", "type": "book_section", "title": "Variable elimination for scalable receding horizon temporal logic planning", "book_title": "2015 American Control Conference (ACC)", "author": [ { "family_name": "F\u00e4lt", "given_name": "Mattias", "clpid": "F\u00e4lt-M" }, { "family_name": "Raman", "given_name": "Vasumathi", "clpid": "Raman-V" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Correct-by-construction synthesis of high-level reactive control relies on the use of formal methods to generate controllers with provable guarantees on their behavior. While this approach has been successfully applied to a wide range of systems and environments, it scales poorly. A receding horizon framework mitigates this computational blowup, by decomposing the global control problem into several tractable subproblems. The existence of a global controller is ensured through symbolic checks of the specification, and local controllers are synthesized when needed. This reduces the size of the synthesized strategy, but still scales poorly for problems with dynamic environments because of the large number of environment strategies in each subproblem. Ad-hoc methods to locally restrict the environment come with the risk of losing correctness. We present a method for reducing the size of these subproblems by eliminating locally redundant variables, while maintaining correctness of the local (and thus global) controllers. We demonstrate the method using an autonomous car example, on problem sizes that were previously unsolvable due to the number of variables in the environment. We also demonstrate how the reduced specifications can be used to identify opportunities for reusing the synthesized local controllers.", "doi": "10.1109/ACC.2015.7171013", "isbn": "978-1-4799-8685-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-07", "pages": "1917-1922" }, { "id": "authors:958cd-6r359", "collection": "authors", "collection_id": "958cd-6r359", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161128-165454738", "type": "book_section", "title": "Cross-entropy temporal logic motion planning", "book_title": "HSCC '15 Proceedings of the 18th International Conference on Hybrid Systems: Computation and Control", "author": [ { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Girard", "given_name": "Antoine", "clpid": "Girard-A" }, { "family_name": "Sankaranarayanan", "given_name": "Sriram", "clpid": "Sankaranarayanan-S" } ], "abstract": "This paper presents a method for optimal trajectory generation for discrete-time nonlinear systems with linear temporal logic (LTL) task specifications. Our approach is based on recent advances in stochastic optimization algorithms for optimal trajectory generation. These methods rely on estimation of the rare event of sampling optimal trajectories, which is achieved by incrementally improving a sampling distribution so as to minimize the cross-entropy. A key component of these stochastic optimization algorithms is determining whether or not a trajectory is collision-free. We generalize this collision checking to efficiently verify whether or not a trajectory satisfies a LTL formula. Interestingly, this verification can be done in time polynomial in the length of the LTL formula and the trajectory. We also propose a method for efficiently re-using parts of trajectories that only partially satisfy the specification, instead of simply discarding the entire sample. Our approach is demonstrated through numerical experiments involving Dubins car and a generic point-mass model subject to complex temporal logic task specifications.", "doi": "10.1145/2728606.2728635", "isbn": "978-1-4503-3433-4", "publisher": "ACM", "place_of_publication": "New York, NY", "publication_date": "2015-04", "pages": "269-278" }, { "id": "authors:53ztk-tph58", "collection": "authors", "collection_id": "53ztk-tph58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150514-135540768", "type": "book_section", "title": "Reactive Synthesis from Signal Temporal Logic Specifications", "book_title": "Proceedings of the 18th International Conference on Hybrid Systems: Computation and Control", "author": [ { "family_name": "Raman", "given_name": "Vasumathi", "clpid": "Raman-V" }, { "family_name": "Donz\u00e9", "given_name": "Alexandre", "clpid": "Donz\u00e9-A" }, { "family_name": "Sadigh", "given_name": "Dorsa", "clpid": "Sadigh-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Seshia", "given_name": "Sanjit A.", "clpid": "Seshia-S-A" } ], "abstract": "We present a counterexample-guided inductive synthesis approach to controller synthesis for cyber-physical systems subject to signal temporal logic (STL) specifications, operating in potentially adversarial nondeterministic environments. We encode STL specifications as mixed integer-linear constraints on the variables of a discrete-time model of the system and environment dynamics, and solve a series of optimization problems to yield a satisfying control sequence. We demonstrate how the scheme can be used in a receding horizon fashion to fulfill properties over unbounded horizons, and present experimental results for reactive controller synthesis for case studies in building climate control and autonomous driving.", "doi": "10.1145/2728606.2728628", "isbn": "978-1-4503-3433-4", "publisher": "Association for Computing Machinery", "place_of_publication": "New York, NY", "publication_date": "2015-04", "pages": "239-248" }, { "id": "authors:w9mbv-7zb84", "collection": "authors", "collection_id": "w9mbv-7zb84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150818-140635950", "type": "book_section", "title": "A risk-aware architecture for resilient spacecraft operations", "book_title": "2015 IEEE Aerospace Conference", "author": [ { "family_name": "McGhan", "given_name": "Catharine L. R.", "clpid": "McGhan-C-L-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Serra", "given_name": "Romain", "clpid": "Serra-R" }, { "family_name": "Ingham", "given_name": "Michel D.", "clpid": "Ingham-M-D" }, { "family_name": "Ono", "given_name": "Masahiro", "clpid": "Ono-Masahiro" }, { "family_name": "Estlin", "given_name": "Tara", "clpid": "Estlin-T" }, { "family_name": "Williams", "given_name": "Brian C.", "clpid": "Williams-B-C" } ], "abstract": "In this paper we discuss a resilient, risk-aware software architecture for onboard, real-time autonomous operations that is intended to robustly handle uncertainty in space-craft behavior within hazardous and unconstrained environments, without unnecessarily increasing complexity. This architecture, the Resilient Spacecraft Executive (RSE), serves three main functions: (1) adapting to component failures to allow graceful degradation, (2) accommodating environments, science observations, and spacecraft capabilities that are not fully known in advance, and (3) making risk-aware decisions without waiting for slow ground-based reactions. This RSE is made up of four main parts: deliberative, habitual, and reflexive layers, and a state estimator that interfaces with all three. We use a risk-aware goal-directed executive within the deliberative layer to perform risk-informed planning, to satisfy the mission goals (specified by mission control) within the specified priorities and constraints. Other state-of-the-art algorithms to be integrated into the RSE include correct-by-construction control synthesis and model-based estimation and diagnosis. We demonstrate the feasibility of the architecture in a simple implementation of the RSE for a simulated Mars rover scenario.", "doi": "10.1109/AERO.2015.7119035", "isbn": "978-1-4799-5379-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-03", "pages": "1-15" }, { "id": "authors:cnxbm-2a321", "collection": "authors", "collection_id": "cnxbm-2a321", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140424-145318619", "type": "book_section", "title": "Designing Robustness to Temperature in a Feedforward Loop Circuit", "book_title": "53rd IEEE Conference on Decision and Control", "author": [ { "family_name": "Sen", "given_name": "Shaunak", "orcid": "0000-0002-1412-8633", "clpid": "Sen-Shaunak" }, { "family_name": "Kim", "given_name": "Jongmin", "orcid": "0000-0002-2713-1006", "clpid": "Kim-Jongmin" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "'Incoherent feedforward loops' represent important biomolecular circuit elements capable of a rich set of dynamic behavior including adaptation and pulsed responses. Temperature can modulate some of these properties through its effect on the underlying reaction rate parameters. It is generally unclear how to design a circuit where these properties are robust to variations in temperature. Here, we address this issue using a combination of tools from control and dynamical systems theory as well as preliminary experimental measurements towards such a design. Using a structured uncertainty representation, we analyze a standard incoherent feedforward loop circuit, noting mechanisms that intrinsically confer temperature robustness to some of its properties. Further, we study design variants that can enhance this robustness to temperature, including different negative feedback configurations as well as conditions for perfect temperature compensation. Finally, we find that the response of an incoherent feedforward loop circuit in cells can change with temperature. These results present groundwork for the design of a temperature-robust incoherent feedforward loop circuit.", "doi": "10.1109/CDC.2014.7040112", "isbn": "978-1-4799-7746-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-12", "pages": "4629-4634" }, { "id": "authors:2zcm1-61z65", "collection": "authors", "collection_id": "2zcm1-61z65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170123-170431903", "type": "book_section", "title": "Modeling the effects of compositional context on promoter activity in an E. coli extract based transcription-translation system", "book_title": "53rd IEEE Conference on Decision and Control", "author": [ { "family_name": "Yeung", "given_name": "Enoch", "orcid": "0000-0001-7630-7429", "clpid": "Yeung-Enoch" }, { "family_name": "Ng", "given_name": "Andrew", "clpid": "Ng-Andrew-H" }, { "family_name": "Kim", "given_name": "Jongmin", "orcid": "0000-0002-2713-1006", "clpid": "Kim-Jongmin" }, { "family_name": "Sun", "given_name": "Zachary Z.", "orcid": "0000-0002-9425-2924", "clpid": "Sun-Zachary-Z" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "One of the fundamental challenges in implementing complex biocircuits is understanding how the spatial arrangement of biological parts impacts biocircuit behavior. We develop a set of synthetic biology parts for systematically probing the effects of spatial arrangement on levels of transcription. Our initial experimental assays prove that even the rearrangement of two biocircuit parts (comprised of a promoter, coding sequence, and terminator) into three spatially distinct orientations (convergent, divergent, and tandem orientation) can exhibit significantly different levels of transcription. These findings motivate the need for mathematical models to describe these spatial context effects. We pose a novel nonlinear massaction kinetics based model that enables the integration of knowledge about spatial or compositional context and canonical descriptions of transcriptional dynamics. Our findings suggest that compositional context plays a role in biocircuit part performance and comprise an important piece of biocircuit interconnection theory.", "doi": "10.1109/CDC.2014.7040234", "isbn": "978-1-4673-6090-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-12", "pages": "5405-5412" }, { "id": "authors:05jmq-v7j52", "collection": "authors", "collection_id": "05jmq-v7j52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170124-175050123", "type": "book_section", "title": "Model predictive control with signal temporal logic specifications", "book_title": "53rd IEEE Conference on Decision and Control", "author": [ { "family_name": "Raman", "given_name": "Vasumathi", "clpid": "Raman-V" }, { "family_name": "Donz\u00e9", "given_name": "Alexandre", "clpid": "Donz\u00e9-A" }, { "family_name": "Maasoumy", "given_name": "Mehdi", "clpid": "Maasoumy-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sangiovanni-Vincentelli", "given_name": "Alberto", "orcid": "0000-0003-1298-8389", "clpid": "Sangiovanni-Vincentelli-A-L" }, { "family_name": "Seshia", "given_name": "Sanjit A.", "clpid": "Seshia-S-A" } ], "abstract": "We present a mathematical programming-based method for model predictive control of discrete-time cyber-physical systems subject to signal temporal logic (STL) specifications. We describe the use of STL to specify a wide range of properties of these systems, including safety, response and bounded liveness. For synthesis, we encode STL specifications as mixed integer-linear constraints on the system variables in the optimization problem at each step of a model predictive control framework. We present experimental results for controller synthesis for building energy and climate control.", "doi": "10.1109/CDC.2014.7039363", "isbn": "978-1-4673-6090-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-12", "pages": "81-87" }, { "id": "authors:ypc43-0k255", "collection": "authors", "collection_id": "ypc43-0k255", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150402-125326775", "type": "book_section", "title": "A Compositional Approach to Stochastic Optimal Control with Co-safe Temporal Logic Specifications", "book_title": "2014 IEEE/RSJ International Conference on Intelligent Robots and Systems", "author": [ { "family_name": "Horowitz", "given_name": "Matanya B.", "clpid": "Horowitz-M-B" }, { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We introduce an algorithm for the optimal control of stochastic nonlinear systems subject to temporal logic constraints on their behavior. We compute directly on the state space of the system, avoiding the expensive pre-computation of a discrete abstraction. An automaton that corresponds to the temporal logic specification guides the computation of a control policy that maximizes the probability that the system satisfies the specification. This reduces controller synthesis to solving a sequence of stochastic constrained reachability problems. Each individual reachability problem is solved via the Hamilton-Jacobi-Bellman (HJB) partial differential equation of stochastic optimal control theory. To increase the efficiency of our approach, we exploit a class of systems where the HJB equation is linear due to structural assumptions on the noise. The linearity of the partial differential equation allows us to pre-compute control policy primitives and then compose them, at essentially zero cost, to conservatively satisfy a complex temporal logic specification.", "doi": "10.1109/IROS.2014.6942750", "isbn": "978-1-4799-6934-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-09", "pages": "1466-1473" }, { "id": "authors:kagek-80764", "collection": "authors", "collection_id": "kagek-80764", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150320-093857002", "type": "book_section", "title": "Collaborative System Identification via Parameter Consensus", "book_title": "2014 American Control Conference", "author": [ { "family_name": "Papusha", "given_name": "Ivan", "clpid": "Papusha-I" }, { "family_name": "Lavretsky", "given_name": "Eugene", "clpid": "Lavretsky-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Classical schemes in system identification and adaptive control often rely on persistence of excitation to guarantee parameter convergence, which may be difficult to achieve with a single agent and a single input. Inspired by consensus systems, we extend classical parameter adaptation to the multi agent setting by combining an adaptive gradient law with consensus dynamics. The gradient law represents the main learning signal, while consensus dynamics attract each agent's parameter estimates toward those of its neighbors. We show that the resulting decentralized online parameter estimator can be used to identify the true parameters of all agents, even if no single agent employs a persistently exciting input.", "doi": "10.1109/ACC.2014.6858938", "isbn": "978-1-4799-3272-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-06", "pages": "13-19" }, { "id": "authors:ff18x-hpc96", "collection": "authors", "collection_id": "ff18x-hpc96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150320-085455694", "type": "book_section", "title": "Exact Stability Analysis of Discrete-Time Linear Systems with Stochastic Delays", "book_title": "2014 American Control Conference", "author": [ { "family_name": "Gomez", "given_name": "Marcella M.", "clpid": "Gomez-M-M" }, { "family_name": "Qin", "given_name": "Wubing B.", "clpid": "Qin-W-B" }, { "family_name": "Orosz", "given_name": "G\u00e1bor", "orcid": "0000-0002-9000-3736", "clpid": "Orosz-G" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper provides analytical results regarding the stability of linear discrete-time systems with stochastic delays. Necessary and sufficient stability conditions are derived by using the second moment dynamics which can be used to draw stability charts. The results are applied to a simple connected vehicle system where the stability regions are compared to those given by the mean dynamics. Our results reveal some fundamental limitations of connected cruise control which becomes more significant as the packet drop ratio increases.", "doi": "10.1109/ACC.2014.6859470", "isbn": "978-1-4799-3272-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-06", "pages": "5534-5539" }, { "id": "authors:6bdnw-8b104", "collection": "authors", "collection_id": "6bdnw-8b104", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150320-090407457", "type": "book_section", "title": "A scalable formulation for engineering combination therapies for evolutionary dynamics of disease", "book_title": "2014 American Control Conference", "author": [ { "family_name": "Jonsson", "given_name": "Vanessa", "clpid": "Jonsson-V-D" }, { "family_name": "Rantzer", "given_name": "Anders", "clpid": "Rantzer-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "It has been shown that optimal controller synthesis for positive systems can be formulated as a linear program. Leveraging these results, we propose a scalable iterative algorithm for the systematic design of sparse, small gain feedback strategies that stabilize the evolutionary dynamics of a generic disease model. We achieve the desired feedback structure by augmenting the optimization problems with \u2113_1 and \u2113_2 regularization terms, and illustrate our method on an example inspired by an experimental study aimed at finding appropriate HIV neutralizing antibody therapy combinations in the presence of escape mutants.", "doi": "10.1109/ACC.2014.6859452", "isbn": "978-1-4799-3272-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2014-06", "pages": "2771-2778" }, { "id": "authors:111zc-hgm46", "collection": "authors", "collection_id": "111zc-hgm46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190329-155946621", "type": "book_section", "title": "Reverse engineering combination therapies for evolutionary dynamics of disease: An H\u221e approach", "book_title": "52nd IEEE Conference on Decision and Control", "author": [ { "family_name": "Jonsson", "given_name": "Vanessa", "clpid": "Jonsson-V-D" }, { "family_name": "Matni", "given_name": "Nikolai", "orcid": "0000-0003-4936-3921", "clpid": "Matni-N" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We propose a general algorithm for the systematic design of feedback strategies to stabilize the evolutionary dynamics of a generic disease model using an H\u221e approach. We show that designing therapy concentrations can be cast as an H\u221e state feedback synthesis problem, where the feedback gain is constrained to not only be strictly diagonal, but also that its diagonal elements satisfy an overdetermined set of linear equations. Leveraging recent results in positive systems, we develop an algorithm that always yields a stabilizing controller.", "doi": "10.1109/CDC.2013.6760185", "isbn": "978-1-4673-5714-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-12", "pages": "2060-2065" }, { "id": "authors:gs7qf-dws25", "collection": "authors", "collection_id": "gs7qf-dws25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190327-160859814", "type": "book_section", "title": "Dynamic state estimation in distributed aircraft electric control systems via adaptive submodularity", "book_title": "52nd IEEE Conference on Decision and Control", "author": [ { "family_name": "Maillet", "given_name": "Quentin", "clpid": "Maillet-Q" }, { "family_name": "Xu", "given_name": "Huan", "clpid": "Xu-Huan" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of estimating the discrete state of an aircraft electric system under a distributed control architecture through active sensing. The main idea is to use a set of controllable switches to reconfigure the system in order to gather more information about the unknown state. By adaptively making a sequence of reconfiguration decisions with uncertain outcome, then correlating measurements and prior information to make the next decision, we aim to reduce the uncertainty. A greedy strategy is developed that maximizes the one-step expected uncertainty reduction. By exploiting recent results on adaptive submodularity, we give theoretical guarantees on the worst-case performance of the greedy strategy. We apply the proposed method in a fault detection scenario where the discrete state captures possible faults in various circuit components. In addition, simple abstraction rules are proposed to alleviate state space explosion and to scale up the strategy. Finally, the efficiency of the proposed method is demonstrated empirically on different circuits.", "doi": "10.1109/CDC.2013.6760755", "isbn": "978-1-4673-5714-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-12", "pages": "5497-5503" }, { "id": "authors:jae6g-jks92", "collection": "authors", "collection_id": "jae6g-jks92", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140411-072530586", "type": "book_section", "title": "Automaton-Guided Controller Synthesis for Nonlinear Systems with Temporal Logic", "book_title": "2013 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", "author": [ { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Amato", "given_name": "N.", "clpid": "Amato-N" } ], "abstract": "We develop a method for the control of discrete-time nonlinear systems subject to temporal logic specifications. Our approach uses a coarse abstraction of the system and an automaton representing the temporal logic specification to guide the search for a feasible trajectory. This decomposes the search for a feasible trajectory into a series of constrained reachability problems. Thus, one can create controllers for any system for which techniques exist to compute (approximate) solutions to constrained reachability problems. Representative techniques include sampling-based methods for motion planning, reachable set computations for linear systems, and graph search for finite discrete systems. Our approach avoids the expensive computation of a discrete abstraction, and its implementation is amenable to parallel computing. We demonstrate our approach with numerical experiments on temporal logic motion planning problems with high-dimensional (10+ states) continuous systems.", "doi": "10.1109/IROS.2013.6696978", "isbn": "978-1-4673-6358-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-11", "pages": "4332-4339" }, { "id": "authors:mh42m-yaw59", "collection": "authors", "collection_id": "mh42m-yaw59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190403-103445318", "type": "book_section", "title": "Pre-orders for reasoning about stability properties with respect to input of hybrid systems", "book_title": "2013 Proceedings of the International Conference on Embedded Software (EMSOFT)", "author": [ { "family_name": "Prabhakar", "given_name": "Pavithra", "clpid": "Prabhakar-P" }, { "family_name": "Liu", "given_name": "Jun", "clpid": "Liu-Jun" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Pre-orders on systems are the basis for abstraction based verification of systems. In this paper, we investigate pre-orders for reasoning about stability with respect to inputs of hybrid systems. First, we present a superposition type theorem which gives a characterization of the classical incremental input-to-state stability of continuous systems in terms of the traditional \u03b5-\u03b4 definition of stability. We use this as the basis for defining a notion of incremental input-to-state stability of hybrid systems. Next, we present a pre-order on hybrid systems which preserves incremental input-to-state stability, by extending the classical definitions of bisimulation relations on systems with input, with uniform continuity constraints. We show that the uniform continuity is a necessary requirement by exhibiting counter-examples to show that weaker notions of input bisimulation with just continuity requirements do not suffice to preserve stability. Finally, we demonstrate that the definitions are useful, by exhibiting concrete abstraction functions which satisfy the definitions of pre-orders.", "doi": "10.1109/EMSOFT.2013.6658602", "isbn": "978-1-4799-1443-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-10", "pages": "1-10" }, { "id": "authors:c08vv-wpk47", "collection": "authors", "collection_id": "c08vv-wpk47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130715-075915746", "type": "book_section", "title": "Biomolecular resource utilization in elementary cell-free gene circuits", "book_title": "2013 American Control Conference (ACC)", "author": [ { "family_name": "Siegal-Gaskins", "given_name": "Dan", "clpid": "Siegal-Gaskins-D" }, { "family_name": "Noireaux", "given_name": "Vincent", "orcid": "0000-0002-5213-273X", "clpid": "Noireaux-V" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We present a detailed dynamical model of the behavior of transcription-translation circuits in vitro that makes explicit the roles played by essential molecular resources. A set of simple two-gene test circuits operating in a cell-free biochemical 'breadboard' validate this model and highlight the consequences of limited resource availability. In particular, we are able to confirm the existence of biomolecular 'crosstalk' and isolate its individual sources. The implications of crosstalk for biomolecular circuit design and function are discussed.", "doi": "10.1109/ACC.2013.6580053", "isbn": "978-1-4799-0177-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "1531-1536" }, { "id": "authors:wnk27-54p79", "collection": "authors", "collection_id": "wnk27-54p79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131219-094019593", "type": "book_section", "title": "Computing augmented finite transition systems to synthesize switching protocols for polynomial switched systems", "book_title": "2013 American Control Conference (ACC)", "author": [ { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Liu", "given_name": "Jun", "clpid": "Liu-Jun" }, { "family_name": "Prabhakar", "given_name": "Pavithra", "clpid": "Prabhakar-P" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This work is motivated by the problem of synthesizing mode sequences for continuous-time polynomial switched systems in order to guarantee that the trajectories of the system satisfy certain high-level specifications expressed in linear temporal logic. We use augmented finite transition systems as abstract models of continuous switched systems. Augmented finite transition systems are equipped with liveness properties that can be used to enforce progress in accordance with the underlying dynamics. We then introduce abstraction and refinement relations that induce a preorder on this class of finite transition systems. By construction, the resulting preorder respects the feasibility (i.e., realizability) of the synthesis problem. Hence, existence of a discrete switching strategy for one of these abstract finite transition systems guarantees the existence of a mode sequence for the continuous system such that all of its trajectories satisfy the specification. We also present an algorithm, which can be implemented using sum-of-squares based relaxations, to compute such high fidelity abstract models in a computationally tractable way. Finally, these ideas are illustrated on an example.", "isbn": "978-1-4799-0177-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "6237-6244" }, { "id": "authors:a4g6k-46g65", "collection": "authors", "collection_id": "a4g6k-46g65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190403-105326642", "type": "book_section", "title": "Feedback architectures to regulate flux of components in artificial gene networks", "book_title": "2013 American Control Conference", "author": [ { "family_name": "Giordano", "given_name": "Giulia", "clpid": "Giordano-G" }, { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper focuses on the regulation of RNA production for in vitro synthetic gene networks. We consider the problem of matching the production rate of several RNA species concurrently transcribed to form RNA complexes. We design regulatory feedback loops based on two schemes: negative auto-regulation (which can minimize the potentially harmful amount of molecules not used to form products) and cross-activation (which can maximize the overall output flux). We analyze numerically the performance of these schemes: in both cases, transcription rate matching can be achieved through proper feedback constants; negative feedback is faster and maintains stability. A possible experimental implementation of a three and four genes negative feedback architecture is also numerically studied.", "doi": "10.1109/ACC.2013.6580572", "isbn": "978-1-4799-0177-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "4747-4752" }, { "id": "authors:32w4c-kan37", "collection": "authors", "collection_id": "32w4c-kan37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131219-095517199", "type": "book_section", "title": "Design and implementation of a biomolecular circuit for tracking protein concentration", "book_title": "2013 American Control Conference (ACC)", "author": [ { "family_name": "de los Santos", "given_name": "Emmanuel L. C.", "clpid": "de-los-Santos-E-L-C" }, { "family_name": "Hsiao", "given_name": "Victoria", "orcid": "0000-0001-9297-1522", "clpid": "Hsiao-Victoria" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes the design, modeling, synthesis and preliminary validation of a protein concentration regulator circuit. The circuit is designed to maintain the level of a target protein to a reference level, specified by the amount of another protein. This is implemented using a single negative feedback loop that inhibits the production of the target protein once its concentration is equal to the reference amount. A mathematical model consisting of a set of ODEs is derived from mass action laws and Hill function approximations of protein production. Steady-state analysis of the model is used to predict parameter sensitivity and experimental behavior. We implemented this circuit in E. coli using scaffold-based sequestration and transcriptional activation. Preliminary experimental results show the system matching predictions from our model and performing the expected task.", "doi": "10.1109/ACC.2013.6580175", "isbn": "978-1-4799-0177-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "2290-2294" }, { "id": "authors:d30r8-zpb47", "collection": "authors", "collection_id": "d30r8-zpb47", "cite_using_url": "https://resolver.caltech.edu/CaltechCDSTR:2012.002", "type": "book_section", "title": "Convex optimal uncertainty quantification: Algorithms and a case study in energy storage placement for power grids", "book_title": "2013 American Control Conference (ACC)", "author": [ { "family_name": "Han", "given_name": "Shuo", "clpid": "Han-Shuo" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Tao", "given_name": "Molei", "clpid": "Tao-Molei" }, { "family_name": "Owhadi", "given_name": "Houman", "orcid": "0000-0002-5677-1600", "clpid": "Owhadi-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "How does one evaluate the performance of a stochastic system in the absence of a perfect model (i.e. probability distribution)? We address this question under the framework of optimal uncertainty quantification (OUQ), which is an information-based approach for worst-case analysis of stochastic systems. We are able to generalize previous results and show that the OUQ problem can be solved using convex optimization when the function under evaluation can be expressed in a polytopic canonical form (PCF). We also propose iterative methods for scaling the convex formulation to larger systems. As an application, we study the problem of storage placement in power grids with renewable generation. Numerical simulation results for simple artificial examples as well as an example using the IEEE 14-bus test case with real wind generation data are presented to demonstrate the usage of OUQ analysis.", "isbn": "978-1-4799-0177-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "1130-1137" }, { "id": "authors:czn3c-e7a25", "collection": "authors", "collection_id": "czn3c-e7a25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-094726571", "type": "book_section", "title": "Efficient reactive controller synthesis for a fragment of linear temporal logic", "book_title": "2013 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Motivated by robotic motion planning, we develop a framework for control policy synthesis for both non-deterministic transition systems and Markov decision processes that are subject to temporal logic task specifications. We introduce a fragment of linear temporal logic that can be used to specify common motion planning tasks such as safe navigation, response to the environment, persistent coverage, and surveillance. This fragment is computationally efficient; the complexity of control policy synthesis is a doubly-exponential improvement over standard linear temporal logic for both non-deterministic transition systems and Markov decision processes. This improvement is possible because we compute directly on the original system, as opposed to the automata-based approach commonly used. We give simulation results for representative motion planning tasks and compare to generalized reactivity.", "doi": "10.1109/ICRA.2013.6631296", "isbn": "978-1-4673-5641-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-05", "pages": "5033-5040" }, { "id": "authors:ms5d0-vmm67", "collection": "authors", "collection_id": "ms5d0-vmm67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-090815397", "type": "book_section", "title": "Robot navigation in dense human crowds: the case for cooperation", "book_title": "2013 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Trautman", "given_name": "Peter", "clpid": "Trautman-P" }, { "family_name": "Ma", "given_name": "Jeremy", "clpid": "Ma-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Krause", "given_name": "Andreas", "orcid": "0000-0001-7260-9673", "clpid": "Krause-A" } ], "abstract": "We consider mobile robot navigation in dense human crowds. In particular, we explore two questions. Can we design a navigation algorithm that encourages humans to cooperate with a robot? Would such cooperation improve navigation performance? We address the first question by developing a probabilistic predictive model of cooperative collision avoidance and goal-oriented behavior by extending the interacting Gaussian processes approach to include multiple goals and stochastic movement duration. We answer the second question with an extensive quantitative study of robot navigation in dense human crowds (488 runs completed), specifically testing how cooperation models effect navigation performance. We find that the \"multiple goal\" interacting Gaussian processes algorithm performs comparably with human teleoperators in crowd densities near 1 person/m^2, while a state of the art noncooperative planner exhibits unsafe behavior more than 3 times as often as this multiple goal extension, and more than twice as often as the basic interacting Gaussian processes. Furthermore, a reactive planner based on the widely used \"dynamic window\" approach fails for crowd densities above 0.55 people/m^2. Based on these experimental results, and previous theoretical observations, we conclude that a cooperation model is important for safe and efficient robot navigation in dense human crowds.", "doi": "10.1109/ICRA.2013.6630866", "isbn": "978-1-4673-5641-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-05", "pages": "2153-2160" }, { "id": "authors:1dmyy-1cj34", "collection": "authors", "collection_id": "1dmyy-1cj34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-125512319", "type": "book_section", "title": "Motion planning in observations space with learned diffeomorphism models", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Nilsson", "given_name": "Adam", "clpid": "Nilsson-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of planning motions in observations space, based on learned models of the dynamics that associate to each action a diffeomorphism of the observations domain. For an arbitrary set of diffeomorphisms, this problem must be formulated as a generic search problem. We adapt established algorithms of the graph search family. In this scenario, node expansion is very costly, as each node in the graph is associated to an uncertain diffeomorphism and corresponding predicted observations. We describe several improvements that ameliorate performance: the introduction of better image similarities to use as heuristics; a method to reduce the number of expanded nodes by preliminarily identifying redundant plans; and a method to pre-compute composite actions that make the search efficient in all directions.", "doi": "10.1109/ICRA.2013.6630973", "publisher": "IEEE", "publication_date": "2013-05" }, { "id": "authors:n2y0r-e1e51", "collection": "authors", "collection_id": "n2y0r-e1e51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-105809953", "type": "book_section", "title": "Just-in-time synthesis for reactive motion planning with temporal logic", "book_title": "2013 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The cost of the great expressivity of motion planning subject to temporal logic formulae is intractability. Recent advances in sampling-based methods seem to be only applicable to \"low-level\" control. The problem of realizing \"high-level\" controllers that satisfy a temporal logic specification does not readily admit approximations, unless the notion of correctness is relaxed as might be achieved with probabilistic variants of temporal logics. In this paper, we argue that not all possible environment (uncontrolled) behaviors need to be explicitly planned for, but rather short-time strategies can be generated online while maintaining global correctness. We achieve this by separating feasibility from controller synthesis, using metrics from the underlying continuous state space to ensure short-time strategies chained together provide globally correct behavior.", "doi": "10.1109/ICRA.2013.6631298", "isbn": "978-1-4673-5641-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-05", "pages": "5048-5053" }, { "id": "authors:twfm3-zjr81", "collection": "authors", "collection_id": "twfm3-zjr81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-131326509", "type": "book_section", "title": "Patching task-level robot controllers based on a local \u00b5-calculus formula", "book_title": "2013 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Prabhakar", "given_name": "Pavithra", "clpid": "Prabhakar-P" }, { "family_name": "Jose", "given_name": "Alex B.", "clpid": "Jose-A-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We present a method for mending strategies for GR(1) specifications. Given the addition or removal of edges from the game graph describing a problem (essentially transition rules in a GR(1) specification), we apply a \u03bc-calculus formula to a neighborhood of states to obtain a \"local strategy\" that navigates around the invalidated parts of an original synthesized strategy. Our method may thus avoid global resynthesis while recovering correctness with respect to the new specification. We illustrate the results both in simulation and on physical hardware for a planar robot surveillance task.", "doi": "10.1109/ICRA.2013.6631229", "isbn": "978-1-4673-5643-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-05", "pages": "4588-4595" }, { "id": "authors:926s7-aa297", "collection": "authors", "collection_id": "926s7-aa297", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130719-105708428", "type": "book_section", "title": "An aircraft electric power testbed for validating automatically synthesized reactive control protocols", "book_title": "Proceedings of the 16th international conference on Hybrid systems: computation and control", "author": [ { "family_name": "Rogersten", "given_name": "Robert", "clpid": "Rogersten-R" }, { "family_name": "Xu", "given_name": "Huan", "clpid": "Xu-H" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Belta", "given_name": "Calin", "clpid": "Belta-C" }, { "family_name": "Ivan\u010di\u0107", "given_name": "Franjo", "clpid": "Ivan\u010di\u0107-F" } ], "abstract": "Modern aircraft increasingly rely on electric power for subsystems that have traditionally run on mechanical power. The complexity and safety-criticality of aircraft electric power systems have therefore increased, rendering the design of these systems more challenging. This work is motivated by the potential that correct-by-construction reactive controller synthesis tools may have in increasing the effectiveness of the electric power system design cycle. In particular, we have built an experimental hardware platform that captures some key elements of aircraft electric power systems within a simplified setting. We intend to use this platform for validating the applicability of theoretical advances in correct-by-construction control synthesis and for studying implementation-related challenges. We demonstrate a simple design workflow from formal specifications to auto-generated code that can run on software models and be used in hardware implementation. We show some preliminary results with different control architectures on the developed hardware testbed.", "doi": "10.1145/2461328.2461344", "isbn": "978-1-4503-1567-8", "publisher": "Association for Computing Machinery", "place_of_publication": "New York, NY", "publication_date": "2013-04", "pages": "89-94" }, { "id": "authors:3tvb6-9pv80", "collection": "authors", "collection_id": "3tvb6-9pv80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140425-112422202", "type": "book_section", "title": "Stability of Discrete-Time Systems with Stochastically Delayed Feedback", "book_title": "Control Conference (ECC), 2013 European", "author": [ { "family_name": "Gomez", "given_name": "Marcella M.", "clpid": "Gomez-M-M" }, { "family_name": "Orosz", "given_name": "G\u00e1bor", "orcid": "0000-0002-9000-3736", "clpid": "Orosz-G" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper investigates the stability of linear systems with stochastic delay in discrete time. Stability of the\nmean and second moment of the non-deterministic system is\ndetermined by a set of deterministic discrete-time equations\nwith distributed delay. A theorem is provided that guarantees convergence of the state with convergence of the second moment, assuming that delays are identically independently distributed. The theorem is applied to a scalar equation where the stability of the equilibrium is determined.", "isbn": "978-3-033-03962-9", "publisher": "IEEE", "place_of_publication": "New York, NY", "publication_date": "2013", "pages": "2609-2614" }, { "id": "authors:h6wj9-cb014", "collection": "authors", "collection_id": "h6wj9-cb014", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131219-103750003", "type": "book_section", "title": "A case study on reactive protocols for aircraft electric power distribution", "book_title": "51st IEEE Conference on Decision and Control", "author": [ { "family_name": "Xu", "given_name": "Huan", "clpid": "Xu-Huan" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of designing a control protocol for the aircraft electric power system that meets system requirements and reacts dynamically to changes in internal system states. We formalize these requirements by translating them into a temporal logic specification language describing the correct behaviors of the system, and apply formal methods to automatically synthesize a controller protocol that satisfies system properties and requirements. Through an example, we perform a design exploration to show the benefits and tradeoffs between centralized and distributed control architectures.", "doi": "10.1109/CDC.2012.6426175", "isbn": "978-1-4673-2065-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-12", "pages": "1124-1129" }, { "id": "authors:faxkf-vwq98", "collection": "authors", "collection_id": "faxkf-vwq98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131220-132617887", "type": "book_section", "title": "Robust control of uncertain Markov Decision Processes with temporal logic specifications", "book_title": "51st IEEE Conference on Decision and Control", "author": [ { "family_name": "Wolff", "given_name": "Eric M.", "clpid": "Wolff-E-M" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We present a method for designing a robust control policy for an uncertain system subject to temporal logic specifications. The system is modeled as a finite Markov Decision Process (MDP) whose transition probabilities are not exactly known but are known to belong to a given uncertainty set. A robust control policy is generated for the MDP that maximizes the worst-case probability of satisfying the specification over all transition probabilities in this uncertainty set. To this end, we use a procedure from probabilistic model checking to combine the system model with an automaton representing the specification. This new MDP is then transformed into an equivalent form that satisfies assumptions for stochastic shortest path dynamic programming. A robust version of dynamic programming solves for a \u03b5-suboptimal robust control policy with time complexity O(log1/\u03b5) times that for the non-robust case.", "doi": "10.1109/CDC.2012.6426174", "isbn": "978-1-4673-2065-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-12", "pages": "3372-3379" }, { "id": "authors:0pm1d-xhn91", "collection": "authors", "collection_id": "0pm1d-xhn91", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-163148693", "type": "book_section", "title": "Reactive controllers for differentially flat systems with temporal logic constraints", "book_title": "2012 IEEE 51st IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Liu", "given_name": "Jun", "clpid": "Liu-Jun" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We propose a procedure for the synthesis of control protocols for systems governed by nonlinear differential equations and constrained by temporal logic specifications. This procedure relies on a particular finite-state abstraction of the underlying continuous dynamics and a discrete representation of the external environmental signals. A two-player game formulation provides computationally efficient means to construct a discrete strategy based on the finite-state model. We focus on systems with differentially flat outputs, which, in a straightforward manner, allows the construction of continuous control signals from the discrete transitions dictated by the discrete strategy. The resulting continuous-time output trajectories are provably guaranteed to robustly satisfy the original specifications.", "doi": "10.1109/CDC.2012.6425981", "isbn": "978-1-4673-2066-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-12", "pages": "7664-7670" }, { "id": "authors:62t20-g3539", "collection": "authors", "collection_id": "62t20-g3539", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247070", "type": "book_section", "title": "Decentralised minimal-time dynamic consensus", "book_title": "2012 American Control Conference (ACC)", "author": [ { "family_name": "Yuan", "given_name": "Ye", "orcid": "0000-0001-7858-0437", "clpid": "Yuan-Ye" }, { "family_name": "Liu", "given_name": "Jun", "orcid": "0000-0002-2504-3651", "clpid": "Liu-Jun" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Gon\u00e7alves", "given_name": "Jorge", "clpid": "Gon\u00e7alves-J-M" } ], "abstract": "This paper considers a group of agents that aim to reach an agreement on individually received time-varying signals by local communication. In contrast to static network averaging problem, the consensus considered in this paper is reached in a dynamic sense. A discrete-time dynamic average consensus protocol can be designed to allow all the agents tracking the average of their reference inputs asymptotically. We propose a minimal-time dynamic consensus algorithm, which only utilises a minimal number of local observations of a randomly picked node in a network to compute the final consensus signal. Our results illustrate that with memory and computational ability, the running time of distributed averaging algorithms can be indeed improved dramatically as suggested by Olshevsky and Tsitsiklis.", "doi": "10.1109/acc.2012.6315298", "isbn": "9781457710964", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-06", "pages": "800-805" }, { "id": "authors:zt6xz-ma385", "collection": "authors", "collection_id": "zt6xz-ma385", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121009-105532954", "type": "book_section", "title": "Switching protocol synthesis for temporal logic specifications", "book_title": "2012 American Control Conference (ACC)", "author": [ { "family_name": "Liu", "given_name": "Jun", "clpid": "Liu-Jun" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of synthesizing a robust switching controller for nonlinear hybrid systems to guarantee that the trajectories of the system satisfy a high level specification expressed in linear temporal logic. Two different types of finite transition systems, namely under-approximations and over-approximations, that abstract the behavior of the underlying continuous dynamical system are defined. Using these finite abstractions, it is possible to leverage tools from logic and automata theory to synthesize discrete mode sequences or strategies. In particular, we show that the discrete synthesis problem for an under-approximation can be reformulated as a model checking problem and that for an over-approximation can be transformed into a two-player game, which can then be solved by using off-the-shelf tools. By construction, existence of a discrete switching strategy for the discrete synthesis problem guarantees the existence of a continuous switching protocol for the continuous synthesis problem, which can be implemented at the continuous level to ensure the correctness of the trajectories for the nonlinear hybrid system. Moreover, in the case of over-approximations, it is shown that one can easily accommodate specifications that require reacting to possibly adversarial external events within the same framework.", "doi": "10.1109/ACC.2012.6315040", "isbn": "978-1-4577-1095-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-06", "pages": "727-734" }, { "id": "authors:c93vh-gnf56", "collection": "authors", "collection_id": "c93vh-gnf56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247242", "type": "book_section", "title": "Temporal logic control of switched affine systems with an application in fuel balancing", "book_title": "2012 American Control Conference (ACC)", "author": [ { "family_name": "Nilsson", "given_name": "Petter", "orcid": "0000-0001-8748-6936", "clpid": "Nilsson-Petter" }, { "family_name": "\u00d6zay", "given_name": "Necmiye", "orcid": "0000-0002-5552-4392", "clpid": "\u00d6zay-Necmiye" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of synthesizing hierarchical controllers for discrete-time switched affine systems subject to exogenous disturbances that guarantee that the trajectories of the system satisfy a high-level specification expressed as a linear temporal logic formula. Our method builds upon recent results on temporal logic planning and embedded controller synthesis. First, the control problem is lifted to a discrete level by constructing a finite transition system that abstracts the behavior of the underlying switched system. At the discrete level, we recast the problem as a two player temporal logic game by treating the environment driven switches as adversaries. The solution strategy for the game (i.e. the discrete plan) is then implemented at the continuous level by solving finite-horizon optimal control problems that establish reachability between discrete states and that compensate the effects of continuous disturbances. We also extend the earlier work by making efficient use of propositions in the temporal logic formula to drive the abstraction procedure and to facilitate the computation of continuous input at implementation time. An aircraft fuel system example is formulated; and solved using the proposed method. This sample problem demonstrates the applicability of the abstraction procedure and correct-by-construction controllers to regulate the fuel levels in multiple tanks during interesting operations like aerial refueling.", "doi": "10.1109/acc.2012.6315141", "isbn": "9781457710964", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-06", "pages": "5302-5309" }, { "id": "authors:vg71z-za941", "collection": "authors", "collection_id": "vg71z-za941", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120703-084401806", "type": "book_section", "title": "Backtracking temporal logic synthesis for uncertain environments", "book_title": "2012 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" } ], "abstract": "This paper considers the problem of synthesizing correct-by-construction robotic controllers in environments with uncertain but fixed structure. \"Environment\" has two notions in this work: a map or \"world\" in which some controlled agent must operate and navigate (i.e., evolve in a configuration space with obstacles); and an adversarial player that selects continuous and discrete variables to try to make the agent fail (as in a game). Both the robot and the environment are subjected to behavioral specifications expressed as an assume-guarantee linear temporal logic (LTL) formula. We then consider how to efficiently modify the synthesized controller when the robot encounters unexpected changes in its environment. The crucial insight is that a portion of this problem takes place in a metric space, which provides a notion of nearness. Thus if a nominal plan fails, we need not resynthesize it entirely, but instead can \"patch\" it locally. We present an algorithm for doing this, prove soundness (correctness of output), and demonstrate it on an example gridworld.", "doi": "10.1109/ICRA.2012.6225208", "isbn": "978-1-4673-1403-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-05", "pages": "5163-5170" }, { "id": "authors:t91fz-aeh12", "collection": "authors", "collection_id": "t91fz-aeh12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120703-110333250", "type": "book_section", "title": "Learning diffeomorphism models of robotic sensorimotor cascades", "book_title": "2012 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The problem of bootstrapping consists in designing agents that can learn from scratch the model of their sensorimotor cascade (the series of robot actuators, the external world, and the robot sensors) and use it to achieve useful tasks. In principle, we would want to design agents that can work for any robot dynamics and any robot sensor(s). One of the difficulties of this problem is the fact that the observations are very high dimensional, the dynamics is nonlinear, and there is a wide range of \"representation nuisances\" to which we would want the agent to be robust. In this paper, we model the dynamics of sensorimotor cascades using diffeomorphisms of the sensel space. We show that this model captures the dynamics of camera and range-finder data, that it can be used for long-term predictions, and that it can capture nonlinear phenomena such as a limited field of view. Moreover, by analyzing the learned diffeomorphisms it is possible to recover the \"linear structure\" of the dynamics independently of the commands representation.", "doi": "10.1109/ICRA.2012.6225318", "isbn": "978-1-4673-1403-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-05", "pages": "3657-3664" }, { "id": "authors:n0ybp-psz75", "collection": "authors", "collection_id": "n0ybp-psz75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120703-105934140", "type": "book_section", "title": "Fault detection and isolation from uninterpreted data in robotic sensorimotor cascades", "book_title": "2012 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "H\u00e5kansson", "given_name": "Magnus", "clpid": "H\u00e5kansson-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "One of the challenges in designing the next generation of robots operating in non-engineered environments is that there seems to be an infinite amount of causes that make the sensor data unreliable or actuators ineffective. In this paper, we discuss what faults are possible to detect using zero modeling effort: we start from uninterpreted streams of observations and commands, and without a prior knowledge of a model of the world. We show that in sensorimotor cascades it is possible to define static faults independently of a nominal model. We define an information-theoretic usefulness of a sensor reading and we show that it captures several kind of sensorimotor faults frequently encountered in practice. We particularize these ideas to models proposed in previous work as suitable candidates for describing generic sensorimotor cascades. We show several examples with camera and range-finder data, and we discuss a possible way to integrate these techniques in an existing robot software architecture.", "doi": "10.1109/ICRA.2012.6225311", "isbn": "978-1-4673-1403-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-05", "pages": "229-236" }, { "id": "authors:6mrfh-9jd54", "collection": "authors", "collection_id": "6mrfh-9jd54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120703-085636525", "type": "book_section", "title": "Towards formal synthesis of reactive controllers for dexterous robotic manipulation", "book_title": "2012 IEEE International Conference on Robotics and Automation (ICRA)", "author": [ { "family_name": "Chinchali", "given_name": "Sandeep", "clpid": "Chinchali-S" }, { "family_name": "Livingston", "given_name": "Scott C.", "clpid": "Livingston-S-C" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In robotic finger gaiting, fingers continuously manipulate an object until joint limitations or mechanical limitations periodically force a switch of grasp. Current approaches to gait planning and control are slow, lack formal guarantees on correctness, and are generally not reactive to changes in object geometry. To address these issues, we apply advances in formal methods to model a gait subject to external perturbations as a two-player game between a finger controller and its adversarial environment. High-level specifications are expressed in linear temporal logic (LTL) and low-level control primitives are designed for continuous kinematics. Simulations of planar manipulation with our synthesized correct-by-construction gait controller demonstrate the benefits of this approach.", "doi": "10.1109/ICRA.2012.6225257", "isbn": "978-1-4673-1403-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-05", "pages": "5183-5189" }, { "id": "authors:6av5c-ej686", "collection": "authors", "collection_id": "6av5c-ej686", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120620-095640251", "type": "book_section", "title": "On synthesizing robust discrete controllers under modeling uncertainty", "book_title": "Proceedings of the 15th ACM international conference on Hybrid Systems: Computation and Control", "author": [ { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Liu", "given_name": "Jun", "clpid": "Liu-Jun" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We investigate the robustness of reactive control protocols\nsynthesized to guarantee system's correctness with respect\nto given temporal logic specifications. We consider uncertainties in open finite transition systems due to unmodeled transitions. The resulting robust synthesis problem is formulated as a temporal logic game. In particular, if the specification is in the so-called generalized reactivity [1] fragment of linear temporal logic, so is the augmented specification in the resulting robust synthesis problem. Hence, the robust synthesis problem belongs to the same complexity class with the nominal synthesis problem, and is amenable to polynomial\ntime solvers. Additionally, we discuss reasoning about\nthe effects of different levels of uncertainties on robust synthesizability and demonstrate the results on a simple robot motion planning scenario.", "doi": "10.1145/2185632.2185648", "isbn": "978-1-4503-1220-2", "publisher": "Association for Computing Machinery", "place_of_publication": "New York, NY", "publication_date": "2012-04", "pages": "85-94" }, { "id": "authors:33kzg-9ca08", "collection": "authors", "collection_id": "33kzg-9ca08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247340", "type": "book_section", "title": "A hovercraft robot that uses insect-inspired visual autocorrelation for motion control in a corridor", "book_title": "2011 IEEE International Conference on Robotics and Biomimetics", "author": [ { "family_name": "Fuller", "given_name": "Sawyer B.", "clpid": "Fuller-S-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we are concerned with the challenge of flight control of computationally-constrained micro-aerial vehicles that must rely primarily on vision to navigate confined spaces. We turn to insects for inspiration. We demonstrate that it is possible to control a robot with inertial, flight-like dynamics in the plane using insect-inspired visual autocor-relators or \"elementary motion detectors\" (EMDs) to detect patterns of visual optic flow. The controller, which requires minimal computation, receives visual information from a small omnidirectional array of visual sensors and computes thrust outputs for a fan pair to stabilize motion along the centerline of a corridor. To design the controller, we provide a frequency-domain analysis of the response of an array of correlators to a flat moving wall. The model incorporates the effects of motion parallax and perspective and provides a means for computing appropriate inter-sensor angular spacing and visual blurring. The controller estimates the state of robot motion by decomposing the correlator response into harmonics, an analogous operation to that performed by tangential cells in the fly. This work constitutes the first-known demonstration of control of non-kinematic inertial dynamics using purely correlators.", "doi": "10.1109/robio.2011.6181498", "isbn": "9781457721380", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-12", "pages": "1474-1481" }, { "id": "authors:pg1xs-af021", "collection": "authors", "collection_id": "pg1xs-af021", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247417", "type": "book_section", "title": "Distributed power allocation for vehicle management systems", "book_title": "2011 50th IEEE Conference on Decision and Control and European Control Conference", "author": [ { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of designing distributed control protocols -for aircraft vehicle management systems-that cooperatively allocate electric power while meeting certain higher level goals and requirements, and dynamically reacting to the changes in the internal system state and external environment. A decentralized control problem is posed where each power distribution unit is equipped with a controller that implements a local protocol to allocate power to a certain subset of loads. We use linear temporal logic as the specification language for describing correct behaviors of the system (e.g., safe operating conditions) as well as the admissible dynamic behavior of the environment due to, for example, wind gusts and changes in system health. We start with a global specification and decompose it into local ones. These decompositions allow the protocols for each local controller to be separately synthesized and locally implemented while guaranteeing the global specifications to hold. Through a design example, we show that by refining the interface rules between power distribution units, it is possible to reduce the total power requirement.", "doi": "10.1109/cdc.2011.6161470", "isbn": "9781612848013", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-12", "pages": "4841-4848" }, { "id": "authors:2t7h1-ngn42", "collection": "authors", "collection_id": "2t7h1-ngn42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247494", "type": "book_section", "title": "Analysis and design of a synthetic transcriptional network for exact adaptation", "book_title": "2011 IEEE Biomedical Circuits and Systems Conference (BioCAS)", "author": [ { "family_name": "Kim", "given_name": "Jongmin", "orcid": "0000-0002-2713-1006", "clpid": "Kim-Jongmin" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper presents a mathematical model for a synthetic transcriptional regulatory network in vitro. This circuit design resembles one of the well-known network motifs, the incoherent feed-forward loop, in which an activator regulates both a gene and a repressor of the gene. Through mathematical analysis, we show how the circuit can be controlled to demonstrate exact adaptation to input signals.", "doi": "10.1109/biocas.2011.6107798", "isbn": "9781457714702", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-11", "pages": "345-348" }, { "id": "authors:88sp6-3am82", "collection": "authors", "collection_id": "88sp6-3am82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120406-140547979", "type": "book_section", "title": "Bootstrapping sensorimotor cascades: a group-theoretic perspective", "book_title": "2011 IEEE/RSJ International Conference on Intelligent Robots and Systems", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The bootstrapping problem consists in designing agents that learn a model of themselves and the world, and utilize it to achieve useful tasks. It is different from other learning problems as the agent starts with uninterpreted observations and commands, and with minimal prior information about the world. in this paper, we give a mathematical formalization of this aspect of the problem. We argue that the vague constrain of having \"no prior information\" can be recast as a precise algebraic condition on the agent: that its behavior is invariant to particular classes of nuisances on the world, which we show can be well represented by actions of groups (diffeomorphisms, permutations, linear transformations) on observations and commans. We then introduce the class of bilinear gradient dynamics sensors (BGDS) as a candidate for learning generic robotic sensorimotor cascades. We show how framing the problem as rejection of group nuisances allows a compact and modular analysis of typical preprocessing stages, such as learning the topology of the sensors. We demonstrate learning and using such models on real-word range-finder and camera date from publicly available datasets.", "doi": "10.1109/IROS.2011.6095151", "isbn": "978-1-61284-454-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-09", "pages": "2056-2063" }, { "id": "authors:qakh7-t5114", "collection": "authors", "collection_id": "qakh7-t5114", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120406-141618413", "type": "book_section", "title": "Containment indicator function construction via numerical conformal mapping", "book_title": "2011 IEEE/RSJ International Conference on Intelligent Robots and Systems", "author": [ { "family_name": "Han", "given_name": "Shuo", "clpid": "Han-Shuo" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In optimal-control-based motion planning, it is often desired to obtain a proper (preferably smooth) function, referred to as the containment indicator function in this paper, that describes the shape of the free space. The paper studies the use of numerical conformal mapping for constructing the containment indicator function for an arbitrary two-dimensional geometry. The idea of using conformal mapping is to transform the original shape of interest into a simpler target shape (e.g. disk, rectangle), which can then be characterized by elementary functions. Computational methods for finding the desired conformal maps are also studied. The procedure can be formulated as a convex optimization problem and computed efficiently.", "doi": "10.1109/IROS.2011.6095037", "isbn": "978-1-61284-454-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-09", "pages": "3017-3022" }, { "id": "authors:44s34-p8q13", "collection": "authors", "collection_id": "44s34-p8q13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120330-135848739", "type": "book_section", "title": "Uncertain semantics, representation nuisances, and necessary invariance properties of bootstrapping agents", "book_title": "2011 IEEE International Conference on Development and Learning", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In the problem of bootstrapping, an agent must learn to use an unknown body, in an unknown world, starting from zero information about the world, its sensors, and its actuators. So far, this fascinating problem has not; been given a proper normalization. In this paper, we provide a possible rigorous definition of one of the key aspects of bootstrapping, namely the fact that an agent must be able to use \"uninterpreted\" observations and commands. We show that this can be formalized by positing the existence of representation nuisances that act on the data, and which must be tolerated by an agent. The classes of nuisances tolerate d in directly encode the assumptions needed about the world, and therefore the agent's ability to solve smaller or larger classes of bootstrapping problem instances. Moreover, we argue that the behavior of an agent that claims optimality must actually be invariant to the representation nuisances, and we discuss several design principles to obtain such invariance.", "doi": "10.1109/DEVLRN.2011.6037313", "isbn": "978-1-61284-989-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-08", "pages": "1-8" }, { "id": "authors:5ntw2-66g34", "collection": "authors", "collection_id": "5ntw2-66g34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247572", "type": "book_section", "title": "Fault-tolerant controller design with applications in power systems and synthetic biology", "book_title": "Proceedings of the 2011 American Control Conference", "author": [ { "family_name": "Sojoudi", "given_name": "Somayeh", "clpid": "Sojoudi-S" }, { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper deals with fault-tolerant controller design for linear time-invariant (LTI) systems with multiple actuators. Given some critical subsets of the actuators, it is assumed that every combination of actuators can fail as long as the set of the remaining actuators includes one of these subsets. Motivated by electric power systems and biological systems, the goal is to design a controller so that the closed-loop system satisfies two properties: (i) stability under all permissible sets of faults and (ii) better performance after clearing every subset of the existing faults in the system. It is shown that a state-feedback controller satisfying these properties exists if and only if a linear matrix inequality (LMI) problem is feasible. This LMI condition is then transformed into an optimal-control condition, which has a useful interpretation. The results are also generalized to output-feedback and decentralized control cases. The efficacy of this work is demonstrated by designing fault-tolerant speed governors for a power system. The results developed here can be extended to more general types of faults, where each fault can possibly affect all state-space matrices of the system.", "doi": "10.1109/acc.2011.5991381", "isbn": "9781457700811", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-07", "pages": "4135-4142" }, { "id": "authors:sv45d-h1e68", "collection": "authors", "collection_id": "sv45d-h1e68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247658", "type": "book_section", "title": "Bootstrapping bilinear models of robotic sensorimotor cascades", "book_title": "2011 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the bootstrapping problem, which consists in learning a model of the agent's sensors and actuators starting from zero prior information, and we take the problem of servoing as a cross-modal task to validate the learned models. We study the class of sensors with bilinear dynamics, for which the derivative of the observations is a bilinear form of the control commands and the observations themselves. This class of models is simple, yet general enough to represent the main phenomena of three representative sensors (field sampler, camera, and range-finder), apparently very different from one another. It also allows a bootstrapping algorithm based on Hebbian learning, and a simple bioplausible control strategy. The convergence properties of learning and control are demonstrated with extensive simulations and by analytical arguments.", "doi": "10.1109/icra.2011.5979844", "isbn": "9781612843865", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-05", "pages": "4318-4325" }, { "id": "authors:w4996-zsc77", "collection": "authors", "collection_id": "w4996-zsc77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247744", "type": "book_section", "title": "Distributed Synthesis of Control Protocols for Smart Camera Networks", "book_title": "2011 IEEE/ACM Second International Conference on Cyber-Physical Systems", "author": [ { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" } ], "abstract": "We considered the problem of designing control protocols for pan-tilt-zoom (PTZ) cameras within a smart camera network where the goal is to guarantee certain temporal logic specifications related to a given surveillance task. We first present a centralized control architecture for assigning PTZ cameras to targets so that the specification is met for any admissible behavior of the targets. Then, in order to alleviate the computational complexity associated with LTL synthesis and to enable implementation of local control protocols on individual PTZ cameras, we propose a distributed synthesis methodology. The main idea is to decompose the global specification into local specifications for each PTZ camera. These decompositions allow the protocols for each camera to be separately synthesized and locally implemented while guaranteeing the global specifications to hold. A thorough design example is presented to illustrate the steps of the proposed procedure.", "doi": "10.1109/iccps.2011.22", "isbn": "9781612846408", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2011-04", "pages": "45-54" }, { "id": "authors:0e1gw-z2s85", "collection": "authors", "collection_id": "0e1gw-z2s85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120522-084524685", "type": "book_section", "title": "TuLiP: a software toolbox for receding horizon temporal logic planning", "book_title": "Proceedings of the 14th international conference on Hybrid systems: computation and control", "author": [ { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Ozay", "given_name": "Necmiye", "clpid": "Ozay-N" }, { "family_name": "Xu", "given_name": "Huan", "clpid": "Xu-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes TuLiP, a Python-based software toolbox for the synthesis of embedded control software that is provably correct with respect to an expressive subset of linear temporal logic (LTL) specifications. TuLiP combines routines for (1) finite state abstraction of control systems, (2) digital design synthesis from LTL specifications, and (3) receding horizon planning. The underlying digital design synthesis routine treats the environment as adversary; hence, the resulting controller is guaranteed to be correct for any admissible environment profile. TuLiP applies the receding horizon framework, allowing the synthesis problem to be broken into a set of smaller problems, and consequently alleviating the computational complexity of the synthesis procedure, while preserving the correctness guarantee.", "doi": "10.1145/1967701.1967747", "isbn": "978-1-4503-0629-4", "publisher": "Association for Computing Machinery (ACM)", "place_of_publication": "New York, NY", "publication_date": "2011-04", "pages": "313-314" }, { "id": "authors:vve9t-shm11", "collection": "authors", "collection_id": "vve9t-shm11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110459012", "type": "book_section", "title": "Formal Synthesis of Embedded Control Software: Application to Vehicle Management Systems", "book_title": "Infotech@Aerospace 2011", "author": [ { "family_name": "Wongpiromsarn", "given_name": "T.", "clpid": "Wongpiromsarn-T" }, { "family_name": "Topcu", "given_name": "U.", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Motivated by the transition from federated to integrated architectures in aerial vehicles, we propose an automated methodology for the synthesis of correct-by-construction control protocols for vehicle management systems. We use linear temporal logic as the specification language for precisely describing correct behaviors of the system as well as the admissible dynamic behavior of the environment due to, for example, wind gusts and changes in the flight conditions. We apply the method in the context of dynamic power allocation among a number of subsystems of varying flight-criticality. The resulting power management protocol is guaranteed to be correct, with respect to the overall system specification, for all admissible environment profiles. This approach also enables reasoning about design tradeoffs such as between efficiency (imposed through formal specifications) and system weight (characterized by the amount of required power generation and energy storage). We present our preliminary results in a simple setting and discuss extensions of the methodology to capture more realistic system and environment models and specifications.", "doi": "10.2514/6.2011-1506", "isbn": "9781600869440", "publisher": "AIAA", "place_of_publication": "Reston, VA", "publication_date": "2011-03-29", "pages": "Art. No. 2011-1506" }, { "id": "authors:shvbe-rf064", "collection": "authors", "collection_id": "shvbe-rf064", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247920", "type": "book_section", "title": "Synthesis of embedded control systems with high sampling frequencies", "book_title": "49th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Sojoudi", "given_name": "Somayeh", "clpid": "Sojoudi-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Motivated by current technological advances in the design of real-time embedded systems, this work deals with the digital control of a continuous-time linear time-invariant (LTI) system whose output can be sampled at a high frequency. Since a typical sampled-data controller operating at a high sampling frequency needs heavy (high-precision) computation to alleviate its sensitivity to measurement and computational errors, the objective is to design a robust hybrid controller for high-frequency applications with limited computational power. To this end, we exploit our recent results on delay-based controller design and propose a digital-control scheme that can implement every continuous-time stabilizing (LTI) controller. This robust hybrid controller, which consists of an ideal sampler, a digital controller, a number of modified second-order holds and possibly a unity feedback, can operate at arbitrarily high sampling frequencies without requiring expensive, high-precision computation. We also discuss how to find a continuous-time LTI controller satisfying prescribed design specifications so that its corresponding digital controller requires the least processing time.", "doi": "10.1109/cdc.2010.5718118", "isbn": "9781424477456", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-12", "pages": "7606-7612" }, { "id": "authors:9m19t-eaz28", "collection": "authors", "collection_id": "9m19t-eaz28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141247830", "type": "book_section", "title": "Tuning a synthetic in vitro oscillator using control-theoretic tools", "book_title": "49th IEEE Conference on Decision and Control (CDC)", "author": [ { "family_name": "Sturk", "given_name": "Christopher", "clpid": "Sturk-C" }, { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper demonstrates the effectiveness of simple control-theoretic tools in generating simulation-guided experiments on a synthetic in vitro oscillator. A theoretical analysis of the behavior of such system is motivated by high cost, time consuming experiments, together with the excessive number of tuning parameters. A simplified model of the synthetic oscillator is chosen to capture only its essential features. The model is analyzed using the small gain theorem and the theory of describing functions. Such analysis reveals what are the parameters that primarily determine when the system can admit stable oscillations. Experimental verification of the theoretical and numerical findings is carried out and confirms the predicted results regarding the role of production and degradation rates.", "doi": "10.1109/cdc.2010.5718111", "isbn": "9781424477456", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-12", "pages": "2554-2559" }, { "id": "authors:1zx0x-m7q59", "collection": "authors", "collection_id": "1zx0x-m7q59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141248010", "type": "book_section", "title": "A bio-plausible design for visual pose stabilization", "book_title": "2010 IEEE/RSJ International Conference on Intelligent Robots and Systems", "author": [ { "family_name": "Han", "given_name": "Shuo", "clpid": "Han-Shuo" }, { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Straw", "given_name": "Andrew D.", "orcid": "0000-0001-8381-0858", "clpid": "Straw-A-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of purely visual pose stabilization (also known as servoing) of a second-order rigid-body system with six degrees of freedom: how to choose forces and torques, based on the current view and a memorized goal image, to steer the pose towards a desired one. Emphasis has been given to the bio-plausibility of the computation, in the sense that the control laws could be in principle implemented on the neural substrate of simple insects. We show that stabilizing laws can be realized by bilinear/quadratic operations on the visual input. This particular computational structure has several numerically favorable characteristics (sparse, local, and parallel), and thus permits an efficient engineering implementation. We show results of the control law tested on an indoor helicopter platform.", "doi": "10.1109/iros.2010.5652857", "isbn": "9781424466740", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-10", "pages": "5679-5686" }, { "id": "authors:4xasg-ds893", "collection": "authors", "collection_id": "4xasg-ds893", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110412-152921583", "type": "book_section", "title": "Simple delay-based implementation of continuous-time controllers", "book_title": "2010 American Control Conference (ACC)", "author": [ { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Sojoudi", "given_name": "Somayeh", "clpid": "Sojoudi-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The objective of this work is to study the benefits that delay can provide in simplifying the control process of large-scale systems, motivated by the availability of different types of delays in man-made and biological systems. We show that a continuous-time linear time-invariant (LTI) controller can be approximated by a simple controller that mainly uses delay blocks instead of integrators. More specifically, three methods are proposed to approximate a pre-designed stabilizing LTI controller arbitrarily precisely by a simple delay-based controller composed of delay blocks, a few integrators and possibly a unity feedback. Different problems associated with the developed approximation procedures, such as finding the optimal number of delay blocks or studying the robustness of the designed controller with respect to delay values, are then addressed.", "doi": "10.1109/ACC.2010.5530439", "isbn": "978-1-4244-7426-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-07", "pages": "5781-5788" }, { "id": "authors:k1s3p-pcf59", "collection": "authors", "collection_id": "k1s3p-pcf59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190326-141248096", "type": "book_section", "title": "Limits on the network sensitivity function for homogeneous multi-agent systems on a graph", "book_title": "Proceedings of the 2010 American Control Conference", "author": [ { "family_name": "Tonetti", "given_name": "Stefania", "clpid": "Tonetti-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper explores some tradeoffs and limits of performance in feedback control of interconnected multi-agent systems, focused on the network sensitivity functions. We consider the interaction topology described by a directed graph and we prove that the sensitivity transfer functions between every pair of agents, arbitrarily connected, can be derived using a version of Mason's direct rule. An analysis of the role of cycles shows that these structures influence and considerably limit the behavior of the system. We also derive a networked version of Bode's integral formula, showing that it still holds for multi-agent systems.", "doi": "10.1109/acc.2010.5530753", "isbn": "9781424474271", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-07", "pages": "3217-3222" }, { "id": "authors:rcvk6-crh09", "collection": "authors", "collection_id": "rcvk6-crh09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-102831203", "type": "book_section", "title": "Experimental demonstration of the dynamics and stability of a low Reynolds number swimmer near a plane wall", "book_title": "Proceedings of the 2010 American Control Conference", "author": [ { "family_name": "Zhang", "given_name": "Sebastian", "clpid": "Zhang-Sebastian" }, { "family_name": "Or", "given_name": "Yizhar", "orcid": "0000-0002-9091-9357", "clpid": "Or-Y" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The motion of microorganisms as well as of tiny robotic swimmers for biomedical applications is governed by low Reynolds number (Re) hydrodynamics, where viscous effects dominate and inertial effects are negligible. This paper presents experimental results that verify theoretical predictions of our recent work which analyzed the dynamics and stability of a low-Re swimmer near a plane wall. The experimental setup uses macro-scale swimmer prototypes which are propelled by rotating cylinders in highly viscous silicone oil. The motion is recorded by a video camera and position measurements are taken by an optical tracking system. The results show good qualitative agreement with our recent theoretical predictions.", "doi": "10.1109/ACC.2010.5530846", "isbn": "978-1-4244-7426-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2010-07", "pages": "4205-4210" }, { "id": "authors:2ddzn-26g38", "collection": "authors", "collection_id": "2ddzn-26g38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161213-153527627", "type": "book_section", "title": "Joint DAC/IWBDA Special Session Engineering Biology: Fundamentals and Applications", "book_title": "DAC '10 Proceedings of the 47th Design Automation Conference", "author": [ { "family_name": "Riedel", "given_name": "Marc", "orcid": "0000-0002-3318-346X", "clpid": "Riedel-M-D" }, { "family_name": "Hassoun", "given_name": "Soha", "clpid": "Hassoun-S" }, { "family_name": "Weiss", "given_name": "Ron", "clpid": "Weiss-R" }, { "family_name": "Silver", "given_name": "Pamela", "clpid": "Silver-P" }, { "family_name": "Anderson", "given_name": "J. Christopher", "clpid": "Anderson-J-C" }, { "family_name": "Murray", "given_name": "Richard", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Sapatnekar", "given_name": "S.", "clpid": "Sapatnekar-S" } ], "abstract": "In the nascent field of synthetic biology, researchers are striving to create biological systems with functionality not seen in nature. This special session features talks that emphasize the fundamental engineering principles underlying this endeavor, highlighting possible synergies with electronic design automation (EDA). Pamela Silver will describe designing and constructing proteins and cells with predictable biological properties. These serve as potential therapeutics, cell-based sensors, factories for generating bio-energy, and bio-remediation. J. Christopher Anderson will demonstrate how complex biological functions can be decomposed into modular devices. He will describe the construction of therapeutic organisms and new tools for building complex systems. Richard Murray will discuss the use of concepts from control and dynamical systems in the analysis and design of biological feedback circuits at the molecular level.", "doi": "10.1145/1837274.1837330", "isbn": "978-1-4503-0002-5", "publisher": "ACM", "place_of_publication": "New York, NY", "publication_date": "2010-06", "pages": "220-221" }, { "id": "authors:b4rgf-whm32", "collection": "authors", "collection_id": "b4rgf-whm32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100701-112021323", "type": "book_section", "title": "Receding Horizon Control for Temporal Logic Specifications", "book_title": "HSSC 10: Proceedings of the 13th ACM International Conference on Hybrid Systems: Computation and Control", "author": [ { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we describe a receding horizon framework that\nsatisfies a class of linear temporal logic specifications sufficient to describe a wide range of properties including safety,\nstability, progress, obligation, response and guarantee. The\nresulting embedded control software consists of a goal generator, a trajectory planner, and a continuous controller.\nThe goal generator essentially reduces the trajectory generation problem to a sequence of smaller problems of short\nhorizon while preserving the desired system-level temporal\nproperties. Subsequently, in each iteration, the trajectory\nplanner solves the corresponding short-horizon problem with\nthe currently observed state as the initial state and generates a feasible trajectory to be implemented by the continuous controller. Based on the simulation property, we\nshow that the composition of the goal generator, trajectory\nplanner and continuous controller and the corresponding receding horizon framework guarantee the correctness of the\nsystem. To handle failures that may occur due to a mismatch between the actual system and its model, we propose\na response mechanism and illustrate, through an example,\nhow the system is capable of responding to certain failures\nand continues to exhibit a correct behavior.", "isbn": "978-1-60558-955-8", "publisher": "ACM", "publication_date": "2010", "pages": "101-110" }, { "id": "authors:1r5ay-1kt71", "collection": "authors", "collection_id": "1r5ay-1kt71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-103804228", "type": "book_section", "title": "Design of insulating devices for in vitro synthetic circuits", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Del Vecchio", "given_name": "Domitilla", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes a synthetic in vitro genetic circuit programmed to work as an insulating device. This circuit is composed of nucleic acids, which can be designed to interact according to user defined rules, and of few proteins that perform catalytic functions. A model of the circuit is derived from first principle biochemical laws. This model is shown to exhibit time-scale separation that makes its output insensitive to downstream time varying loads. Simulation results show the circuit effectiveness and represent the starting point for future experimental testing of the device.", "doi": "10.1109/CDC.2009.5400523", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "4584-4589" }, { "id": "authors:rf1mb-aga48", "collection": "authors", "collection_id": "rf1mb-aga48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-104610564", "type": "book_section", "title": "Compositional stability analysis based on dual decomposition", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Packard", "given_name": "Andrew K.", "clpid": "Packard-A-K" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We propose a compositional stability analysis framework for verifying properties of systems that are interconnections of multiple subsystems. The proposed method assembles stability certificates for the interconnected system based on the certificates for the input-output properties of the subsystems. The decomposition in the analysis is achieved by utilizing dual decomposition ideas from optimization. Decoupled subproblems establish subsystem level input-output properties whereas the \"master\" problem imposes and updates the conditions on the subproblems toward ensuring interconnected system level stability properties. Both global stability analysis and region-of-attraction analysis are discussed.", "doi": "10.1109/CDC.2009.5400309", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "1175-1180" }, { "id": "authors:r120s-4ch11", "collection": "authors", "collection_id": "r120s-4ch11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-105229020", "type": "book_section", "title": "Quantized consensus via adaptive stochastic gossip algorithm", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper is concerned with the distributed averaging problem over a given undirected graph. To enable every vertex to compute the average of the initial numbers sitting on the vertices of the graph, the policy is to pick an edge at random and update the values on its ending vertices based on some rules, but only in terms of the quantized data being exchanged between them. Our recent paper showed that the quantized consensus is reached under a simple updating protocol which deploys a fixed tuning factor. The current paper allows the tuning factor to be time-dependent in order to achieve two goals. First, this makes it possible to study the numerical stability of the protocol with a fixed tuning factor under a small perturbation of this parameter. Furthermore, exploiting a time-varying tuning factor facilitates the implementation of the consensus protocol and pushes the steady state of the system towards an equilibrium point, as opposed to making it oscillatory. The current paper is an important extension of our recent work, which generalizes a finite-dimensional problem to an infinite-dimensional one that is more challenging in nature.", "doi": "10.1109/CDC.2009.5400005", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "5756-5762" }, { "id": "authors:3ks9k-x4k11", "collection": "authors", "collection_id": "3ks9k-x4k11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-132458437", "type": "book_section", "title": "A bio-plausible design for visual attitude stabilization", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Han", "given_name": "Shuo", "clpid": "Han-Shuo" }, { "family_name": "Fuller", "given_name": "Sawyer B.", "clpid": "Fuller-S-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of attitude stabilization using exclusively visual sensory input, and we look for a solution which can satisfy the constraints of a \"bio-plausible\" computation. We obtain a PD controller which is a bilinear form of the goal image, and the current and delayed visual input. Moreover, this controller can be learned using classic neural networks algorithms. The structure of the resulting computation, derived from general principles by imposing a bilinear computation, has striking resemblances with existing models for visual information processing in insects (Reichardt Correlators and lobula plate tangential cells). We validate the algorithms using faithful simulations of the fruit fly visual input.", "doi": "10.1109/CDC.2009.5400408", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "3513-3520" }, { "id": "authors:0pcte-k2z58", "collection": "authors", "collection_id": "0pcte-k2z58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-111541230", "type": "book_section", "title": "Geometric control of particle manipulation in a two-dimensional fluid", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Or", "given_name": "Yizhar", "orcid": "0000-0002-9091-9357", "clpid": "Or-Y" }, { "family_name": "Vankerschaver", "given_name": "Joris", "clpid": "Vankerschaver-J" }, { "family_name": "Kelly", "given_name": "Scott D.", "clpid": "Kelly-S-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Marsden", "given_name": "Jerrold E.", "clpid": "Marsden-J-E" } ], "abstract": "Manipulation of particles suspended in fluids is crucial for many applications, such as precision machining, chemical processes, bio-engineering, and self-feeding of microorganisms. In this paper, we study the problem of particle manipulation by cyclic fluid boundary excitations from a geometric-control viewpoint. We focus on the simplified problem of manipulating a single particle by generating controlled cyclic motion of a circular rigid body in a two-dimensional perfect fluid. We show that the drift in the particle location after one cyclic motion of the body can be interpreted as the geometric phase of a connection induced by the system's hydrodynamics. We then formulate the problem as a control system, and derive a geometric criterion for its nonlinear controllability. Moreover, by exploiting the geometric structure of the system, we explicitly construct a feedback-based gait that results in attraction of the particle towards the rigid body. We argue that our gait is robust and model-independent, and demonstrate it in both perfect fluid and Stokes fluid.", "doi": "10.1109/CDC.2009.5399499", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "19-26" }, { "id": "authors:kkgh6-cjt58", "collection": "authors", "collection_id": "kkgh6-cjt58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-110325145", "type": "book_section", "title": "Receding horizon temporal logic planning for dynamical systems", "book_title": "Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "author": [ { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" }, { "family_name": "Topcu", "given_name": "Ufuk", "clpid": "Topcu-U" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper bridges the advances in computer science and control to allow automatic synthesis of control strategies for complex dynamical systems which are guaranteed, by construction, to satisfy the desired properties even in the presence of adversary. The desired properties are expressed in the language of temporal logic. With its expressive power, a wider class of properties than safety and stability can be specified. The resulting system consists of a discrete planner that plans, in the abstracted discrete domain, a set of transitions of the system to ensure the correct behaviors and a continuous controller that continuously implements the plan. To address the computational difficulties in the synthesis of a discrete planner, we present a receding horizon based scheme for executing finite state automata that essentially reduces the synthesis problem to a set of smaller problems.", "doi": "10.1109/CDC.2009.5399536", "isbn": "978-1-4244-3871-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-12", "pages": "5997-6004" }, { "id": "authors:7a5hx-t6a79", "collection": "authors", "collection_id": "7a5hx-t6a79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-133036019", "type": "book_section", "title": "Real-valued average consensus over noisy quantized channels", "book_title": "American Control Conference, 2009", "author": [ { "family_name": "Censi", "given_name": "Andrea", "orcid": "0000-0001-5162-0398", "clpid": "Censi-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper concerns the average consensus problem\nwith the constraint of quantized communication between\nnodes. A broad class of algorithms is analyzed, in which the\ntransmission strategy, which decides what value to communicate\nto the neighbours, can include various kinds of rounding, probabilistic\nquantization, and bounded noise. The arbitrariness\nof the transmission strategy is compensated by a feedback\nmechanism which can be interpreted as a self-inhibitory action.\nThe result is that the average of the nodes state is not conserved\nacross iterations, and the nodes do not converge to a consensus;\nhowever, we show that both errors can be made as small\nas desired. Bounds on these quantities involve the spectral\nproperties of the graph and can be proved by employing\nelementary techniques of LTI systems analysis.", "doi": "10.1109/ACC.2009.5159872", "isbn": "978-1-4244-4523-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-06", "pages": "4361-4366" }, { "id": "authors:1g2sa-ap737", "collection": "authors", "collection_id": "1g2sa-ap737", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-094244165", "type": "book_section", "title": "On quantized consensus by means of gossip algorithm - Part I: Convergence proof", "book_title": "American Control Conference, 2009", "author": [ { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper is concerned with the distributed\naveraging problem subject to a quantization constraint. Given\na group of agents associated with scalar numbers, it is assumed\nthat each pair of agents can communicate with a prescribed\nprobability, and that the data being exchanged between them\nis quantized. In this part of the paper, it is proved that the\nstochastic gossip algorithm proposed in a recent paper leads\nto reaching the quantized consensus. Some important steady-state properties of the system (after reaching the consensus)\nare also derived. The results developed here hold true for any\narbitrary quantization, provided that the tuning parameter of\nthe gossip algorithm is chosen properly. The expected value of\nthe convergence time is lower and upper bounded in the second\npart of the paper.", "doi": "10.1109/ACC.2009.5160485", "isbn": "978-1-4244-4523-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-06", "pages": "394-401" }, { "id": "authors:kwb3m-7e641", "collection": "authors", "collection_id": "kwb3m-7e641", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-091712132", "type": "book_section", "title": "On quantized consensus by means of gossip algorithm - Part II: Convergence time", "book_title": "2009 American Control Conference", "author": [ { "family_name": "Lavaei", "given_name": "Javad", "clpid": "Lavaei-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper deals with the distributed averaging problem over a connected network of agents, subject to a quantization constraint. It is assumed that at each time update, only a pair of agents can update their own numbers in terms of the quantized data being exchanged. The agents are also required to communicate with one another in a stochastic fashion. In the first part of the paper, it was shown that the quantized consensus is reached by means of a stochastic gossip algorithm proposed in a recent paper, for any arbitrary quantization. The current part of the paper considers the expected value of the time at which the quantized consensus is reached. This quantity (corresponding to the worst case) is lower and upper bounded in terms of the topology of the graph, for uniform quantization. In particular, it is shown that the upper bound is related to the principal minors of the weighted Laplacian matrix. A convex optimization is also proposed to determine the set of probabilities (used to pick a pair of agents) which leads to the fast convergence of the gossip algorithm.", "doi": "10.1109/ACC.2009.5160568", "isbn": "978-1-4244-4523-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-06", "pages": "2958-2965" }, { "id": "authors:tg97z-p0j72", "collection": "authors", "collection_id": "tg97z-p0j72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-135204769", "type": "book_section", "title": "A real-time helicopter testbed for insect-inspired visual flight control", "book_title": "2009 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Han", "given_name": "Shuo", "clpid": "Han-Shuo" }, { "family_name": "Straw", "given_name": "Andrew D.", "orcid": "0000-0001-8381-0858", "clpid": "Straw-A-D" }, { "family_name": "Dickinson", "given_name": "Michael H.", "orcid": "0000-0002-8587-9936", "clpid": "Dickinson-M-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The paper describes an indoor helicopter testbed that allows implementing and testing of bio-inspired control algorithms developed from scientific studies on insects. The helicopter receives and is controlled by simulated sensory inputs (e.g. visual stimuli) generated in a virtual 3D environment, where the connection between the physical world and the virtual world is provided by a video camera tracking system. The virtual environment is specified by a 3D computer model and is relatively simple to modify compared to realistic scenes. This enables rapid examinations of whether a certain control law is robust under various environments, an important feature of insect behavior. As a first attempt, flight stabilization and yaw rate control near hover are demonstrated, utilizing biologically realistic visual stimuli as in the fruit fly Drosophila melanogaster.", "doi": "10.1109/ROBOT.2009.5152667", "isbn": "978-1-4244-2788-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2009-05", "pages": "3055-3060" }, { "id": "authors:ksrb5-sks83", "collection": "authors", "collection_id": "ksrb5-sks83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-143454266", "type": "book_section", "title": "Design and performance of in vitro transcription rate regulatory circuits", "book_title": "47th IEEE Conference on Decision and Control", "author": [ { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper proposes a synthetic in vitro circuit that aims at regulating the rate of RNA transcription through positive feedback interactions. This design is dual to a previously synthesized transcriptional rate regulator based on self-repression. Two DNA templates are designed to interact through their transcripts, creating cross activating feedback loops that will equate their transcription rates at steady state. A mathematical model is developed for this circuit, consisting of a set of ODEs derived from the mass action laws and Michaelis-Menten kinetics involving all the present chemical species. This circuit is then compared to its regulatory counterpart based on negative feedback. A global sensitivity analysis reveals the fundamental features of the two designs by evaluating their equilibrium response to changes in the most crucial parameters of the system.", "doi": "10.1109/CDC.2008.4739253", "isbn": "978-1-4244-3123-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-12", "pages": "161-166" }, { "id": "authors:pr3md-m1f83", "collection": "authors", "collection_id": "pr3md-m1f83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-145008185", "type": "book_section", "title": "Optimal sensor hop selection: Sensor energy minimization and network lifetime maximization with guaranteed system performance", "book_title": "47th IEEE Conference on Decision and Control", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Johansson", "given_name": "Karl Henrik", "clpid": "Johansson-K-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we consider state estimation carried over a sensor network. A fusion center forms a local multi-hop tree of sensors and gateways and fuses the data into a state estimate. It is shown that the optimal estimator over a sensor tree is given by a Kalman filter of certain structure. The number of hops that the sensors use to communicate data with the fusion center is optimized such that either the overall transmission energy is minimized or the network lifetime is maximized. In both cases the fusion center provides a specified level of estimation accuracy. Some heuristic algorithms are proposed which lead to suboptimal solutions in the energy minimization problem, while an algorithm that leads to the global optimal solution is proposed in the lifetime maximization problem. In both cases, the algorithms are shown to have low computational complexity. Examples are provided to demonstrate the theory and algorithms.", "doi": "10.1109/CDC.2008.4738663", "isbn": "978-1-4244-3123-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-12", "pages": "2344-2349" }, { "id": "authors:rddvz-9wc82", "collection": "authors", "collection_id": "rddvz-9wc82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100726-104209965", "type": "book_section", "title": "Kalman Filtering Over A Packet Dropping Network: A Probabilistic Approach", "book_title": "10th Annual Conference on Control, Automation, Robotics, and Vision, 2008", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider the problem of state estimation of a discrete time process over a packet dropping network. Previous pioneering work on Kalman filtering with intermittent observations is concerned with the asymptotic behavior of E[P_k], i.e., the expected value of the error covariance, for a given packet arrival rate. We consider a different performance metric, Pr[P_k \u2264 M], i.e., the probability that P_k is bounded by a given M, and we derive lower and upper bounds on Pr[P_k \u2264 M]. We are also able to recover the results in the literature when using Pr[P_k \u2264 M] as a metric for scalar systems. Examples are provided to illustrate the theory developed in the paper.", "doi": "10.1109/ICARCV.2008.4795489", "isbn": "978-1-4244-2286-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-12", "pages": "41-46" }, { "id": "authors:jbwc2-haj66", "collection": "authors", "collection_id": "jbwc2-haj66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-142007113", "type": "book_section", "title": "Dynamics of escaping flight initiations of Drosophila melanogaster", "book_title": "2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics", "author": [ { "family_name": "Zabala", "given_name": "Francisco A.", "clpid": "Zabala-F-A" }, { "family_name": "Card", "given_name": "Gwyneth M.", "orcid": "0000-0002-7679-3639", "clpid": "Card-G-M" }, { "family_name": "Fontaine", "given_name": "Ebraheem I.", "clpid": "Fontaine-E-I" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Dickinson", "given_name": "Michael H.", "orcid": "0000-0002-8587-9936", "clpid": "Dickinson-M-H" } ], "abstract": "We present a reconstruction of the dynamics of flight initiation from kinematic data extracted from high-speed video recordings of the fruit fly Drosophila melanogaster. The dichotomy observed in this insectpsilas flight initiation sequences, generated by the presence or absence of visual stimuli, clearly generates two contrasting sets of dynamics once the flies become airborne. By calculating reaction forces and moments using the unconstrained motion formulation for a rigid body, we assess the flypsilas responses amidst these two dynamic patterns as a step towards refining our understanding of insect flight control.", "doi": "10.1109/BIOROB.2008.4762921", "isbn": "978-1-4244-2882-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-10", "pages": "1-6" }, { "id": "authors:yxy9x-pem71", "collection": "authors", "collection_id": "yxy9x-pem71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200127-094633815", "type": "book_section", "title": "Robust Model Predictive Control with a Safety Mode: Applied to Small-Body Proximity Operations", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit", "author": [ { "family_name": "Carson", "given_name": "John M., III", "clpid": "Carson-J-M-III" }, { "family_name": "A\u00e7\u0131kme\u015fe", "given_name": "Beh\u00e7et", "clpid": "A\u00e7\u0131kme\u015fe-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "MacMynowski", "given_name": "Douglas G.", "orcid": "0000-0003-1987-9417", "clpid": "MacMartin-D-G" } ], "abstract": "Safe and robust G&C (Guidance and Control) algorithms for onboard implementation are developed by augmenting a model predictive control technique with a safety mode. The application example herein is spacecraft small-body proximity operations where model and constraint uncertainty warrant G&C algorithms with a degree of autonomous, onboard decision capability. The algorithm enforces state and control constraints and merges two operational modes: (I) standard mode guides the spacecraft to the proximity of a target state in a robust and resolvable model-predictive manner, (II) safety mode, if activated, maintains the spacecraft near a safety reference for all time. The algorithm utilizes separate feedforward and feedback components. In standard mode, the feedforward guidance solutions come from a way-point generation algorithm that uses a discrete linear-time-varying dynamics model. This approach provides a convex formulation of the problem (solvable onboard as a second-order cone program) that includes control and state constraints; the safety-mode availability adds a constraint in this standard-mode formulation as well. The feedback guarantees standard-mode resolvability to update the guidance profile in a robust, model-predictive manner. In safety mode, an offline-designed feedforward policy with the added feedback maintains the spacecraft in a hovering state in the proximity of its position at safety-mode activation time; this provides robustness to unexpected state-constraint changes such as unexpected ground proximity during landing operations. A simulation demonstrating both the standard and safety modes is provided for a spacecraft\nautonomous-descent scenario toward a small asteroid with an uncertain gravity model and errors in the surface altitude constraint.", "doi": "10.2514/6.2008-7243", "isbn": "978-1-60086-999-0", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2008-08", "pages": "Art. No. 2008-7243" }, { "id": "authors:mqxny-1w830", "collection": "authors", "collection_id": "mqxny-1w830", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-145441234", "type": "book_section", "title": "Nonlinear lateral control strategy for nonholonomic vehicles", "book_title": "2008 American Control Conference", "author": [ { "family_name": "Linderoth", "given_name": "Magnus", "clpid": "Linderoth-M" }, { "family_name": "Soltesz", "given_name": "Kristian", "clpid": "Soltesz-K" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper proposes an intuitive nonlinear lateral control strategy for trajectory tracking in autonomous nonholonomic vehicles. The controller has been implemented and verified in Alice, Team Caltech's contribution to the 2007 DARPA Urban Challenge competition for autonomous motorcars. A kinematic model is derived. The control law is described and analyzed. Results from simulations and field tests are given and evaluated. Finally, the key features of the proposed controller are reviewed, followed by a discussion of some limitations of the proposed strategy.", "doi": "10.1109/ACC.2008.4586988", "isbn": "978-1-4244-2078-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-06", "pages": "3219-3224" }, { "id": "authors:mt3tg-02637", "collection": "authors", "collection_id": "mt3tg-02637", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-145913467", "type": "book_section", "title": "Convergence properties of dynamic agents consensus networks with broken links", "book_title": "2008 American Control Conference", "author": [ { "family_name": "Di Cairano", "given_name": "S.", "clpid": "Di-Cairano-S" }, { "family_name": "Pasini", "given_name": "A.", "clpid": "Pasini-A" }, { "family_name": "Bemporad", "given_name": "A.", "clpid": "Bemporad-A" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Convergence properties of distributed consensus protocols on networks of dynamical agents have been analyzed by combinations of algebraic graph theory and control theory tools under certain assumptions, such as strong connectivity. Strong connectivity can be regarded as the requirement that the information of each agent propagates to all the others, possibly with intermediate steps and manipulations. However, because of network failures or malicious attacks, it is possible that this assumption no longer holds, so that some agents are only receiving or only transmitting information from other subsets of agents. In this case, strong connectivity is replaced by weak connectivity. We analyze the convergence properties of distributed consensus on directed graphs with weakly connected components. We show conditions for which the agreement is reached, and, for the cases in which such conditions do not hold, we provide bounds on the residual disagreement.", "doi": "10.1109/ACC.2008.4586682", "isbn": "978-1-4244-2078-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-06", "pages": "1362-1367" }, { "id": "authors:0ttgm-fzx60", "collection": "authors", "collection_id": "0ttgm-fzx60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100623-113414565", "type": "book_section", "title": "Safety Verification of Fault Tolerant Goal-based Control Programs with Estimation Uncertainty", "book_title": "American Control Conference, 2008", "author": [ { "family_name": "Braman", "given_name": "Julia M. B.", "clpid": "Braman-J-M-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Fault tolerance and safety verification of control systems that have state variable estimation uncertainty are essential for the success of autonomous robotic systems. A software control architecture called mission data system, developed at the Jet Propulsion Laboratory, uses goal networks as the control program for autonomous systems. Certain types of goal networks can be converted into linear hybrid systems and verified for safety using existing symbolic model checking software. A process for calculating the probability of failure of certain classes of verifiable goal networks due to state estimation uncertainty is presented. A verifiable example task is presented and the failure probability of the control program based on estimation uncertainty is found.", "doi": "10.1109/ACC.2008.4586461", "isbn": "978-1-4244-2078-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-06", "pages": "27-32" }, { "id": "authors:tavz4-qfw65", "collection": "authors", "collection_id": "tavz4-qfw65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100512-105503658", "type": "book_section", "title": "Design, modeling and synthesis of an in vitro transcription rate regulatory circuit", "book_title": "American Control Conference, 2008", "author": [ { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Forsberg", "given_name": "Per-Ola", "clpid": "Forsberg-O-O" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes the design, modeling and realization of a synthetic in vitro circuit that aims at regulating the rate of mRNA transcription. Two DNA templates are designed to interact through their transcripts, creating negative feedback loops that will equate their transcription rates at steady state. A mathematical model is developed for this circuit, consisting of a set of ODEs derived from the mass action laws and Michaelis-Menten kinetics involving all the present chemical species. The DNA strands were accordingly designed, following thermodynamics principles and minimizing unwanted interactions. Preliminary experimental results show that the circuit is performing the expected task, by matching at steady state the transcription rates of the two DNA templates.", "doi": "10.1109/ACC.2008.4586915", "isbn": "978-1-4244-2078-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2008-06", "pages": "2786-2791" }, { "id": "authors:f23by-q5h03", "collection": "authors", "collection_id": "f23by-q5h03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100715-135111003", "type": "book_section", "title": "Situational reasoning for road driving in an urban environment", "book_title": "Intelligent vehicle control systems : proceedings of the 2nd International Workshop on Intelligent Vehicle Control Systems, IVCS 2008", "author": [ { "family_name": "Du Toit", "given_name": "Noel E.", "clpid": "Du-Toit-N-E" }, { "family_name": "Wongpiromsarn", "given_name": "Tichakorn", "clpid": "Wongpiromsarn-T" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Robot navigation in urban environments requires situational reasoning.\nGiven the complexity of the environment and the behavior specified by traffic\nrules, it is necessary to recognize the current situation to impose the correct\ntraffic rules. In an attempt to manage the complexity of the situational reasoning\nsubsystem, this paper describes a finite state machine model to govern the situational\nreasoning process. The logic state machine and its interaction with the\nplanning system are discussed. The approach was implemented on Alice, Team\nCaltech's entry into the 2007 DARPA Urban Challenge. Results from the qualifying\nrounds are discussed. The approach is validated and the shortcomings of\nthe implementation are identified.", "isbn": "978-989-8111-34-0", "publisher": "INSTICC Press", "publication_date": "2008", "pages": "30-39" }, { "id": "authors:77s02-vk389", "collection": "authors", "collection_id": "77s02-vk389", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101105-135641397", "type": "book_section", "title": "Change Sensor Topology When Needed: How to Efficiently Use System Resources in Control and Estimation Over Wireless Networks", "book_title": "46th IEEE Conference on Decision and Control", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Johansson", "given_name": "Karl Henrik", "clpid": "Johansson-K-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "New control paradigms are needed for large networks\nof wireless sensors and actuators in order to efficiently\nutilize system resources. In this paper we consider when\nfeedback control loops are formed locally to detect, monitor, and counteract disturbances that hit a plant at random instances in time and space. A sensor node that detects a disturbance dynamically forms a local multi-hop tree of sensors and fuse the data into a state estimate. It is shown that the optimal estimator over a sensor tree is given by a Kalman filter of certain structure. The tree is optimized such that the overall transmission energy is minimized but guarantees a specified level of estimation accuracy. A sensor network reconfiguration algorithm is presented that leads to a suboptimal solution and has low computational complexity. A linear control law based\non the state estimate is applied and it is argued that it leads to a closed-loop control system that minimizes a quadratic cost function. The sensor network reconfiguration and the feedback control law are illustrated on an example.", "doi": "10.1109/CDC.2007.4434979", "isbn": "978-1-4244-1497-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-12", "pages": "5478-5485" }, { "id": "authors:78v71-3ye02", "collection": "authors", "collection_id": "78v71-3ye02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100923-141354531", "type": "book_section", "title": "Random consensus protocol in large-scale networks", "book_title": "46th IEEE Conference on Decision and Control", "author": [ { "family_name": "Jin", "given_name": "Zhipu", "clpid": "Jin-Zhipu" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "One of the main performance issues for consensus\nprotocols is the convergence speed. In this paper, we focus on the\nconvergence behavior of discrete-time consensus protocols over\nlarge-scale sensor networks with uniformly random deployment,\nwhich are modelled as Poisson random graphs. Instead of\nusing the random rewiring procedure, we introduce a deterministic\nprinciple to locate certain \"chosen nodes\" in the network\nand add \"virtual\" shortcuts among them so that the number\nof iterations to achieve average consensus drops dramatically.\nSimulation results are presented to verify the efficiency of this\napproach. Moreover, a random consensus protocol is proposed,\nin which virtual shortcuts are implemented by random routes.", "doi": "10.1109/CDC.2007.4434765", "isbn": "978-1-4244-1497-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-12", "pages": "4227-4232" }, { "id": "authors:zbwv0-90r27", "collection": "authors", "collection_id": "zbwv0-90r27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100826-114646843", "type": "book_section", "title": "Estimation Schemes for Networked Control Systems Using UDP-Like Communication", "book_title": "46th IEEE Conference on Decision and Control", "author": [ { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this work we consider a class of networked control systems (NCS) when the control signal is sent to the plant via a UDP-like communication protocol, the controller sends a communication packet to the plant across a lossy network but the controller does not receive any acknowledgement signal indicating the status of reception/delivery of the control packet. Standard observer based estimators assume the estimator has knowledge of what control signal is applied to the plant, but under the UDP-like communication scheme the estimator does not know what control is applied. Continuing previous work, we present a simple estimation algorithm consisting of a state estimator and mode observer. For single input systems we can add an extra control signal that guarantees recovery of the fate of the control packet. Using a modified state feedback with the added input we can guarantee the estimation error is bounded as is the expected value of the state. This extra input is removed and sufficient conditions on the system properties are given to assure the estimation remain bounded. Comparisons are made between the algorithm presented and the method of unknown input observer. Simulations are provided to demonstrate the algorithm.", "doi": "10.1109/CDC.2007.4434841", "isbn": "978-1-4244-1497-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-12", "pages": "3945-3951" }, { "id": "authors:z8pcw-2xs29", "collection": "authors", "collection_id": "z8pcw-2xs29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100820-081349938", "type": "book_section", "title": "Safety verification of a fault tolerant reconfigurable autonomous goal-based robotic control system", "book_title": "2007 IEEE/RSJ International Conference on Intelligent Robots and Systems", "author": [ { "family_name": "Braman", "given_name": "Julia M. B.", "clpid": "Braman-J-M-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Wagner", "given_name": "David A.", "clpid": "Wagner-D-A" } ], "abstract": "Fault tolerance and safety verification of control\nsystems are essential for the success of autonomous robotic\nsystems. A control architecture called Mission Data System\n(MDS), developed at the Jet Propulsion Laboratory, takes\na goal-based control approach. In this paper, a method for\nconverting goal network control programs into linear hybrid\nsystems is developed. The linear hybrid system can then be\nverified for safety in the presence of failures using existing\nsymbolic model checkers. An example task is simulated in\nMDS and successfully verified using HyTech, a symbolic model\nchecking software for linear hybrid systems.", "doi": "10.1109/IROS.2007.4399230", "isbn": "978-1-4244-0911-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-11", "pages": "859-864" }, { "id": "authors:wm81w-wgx51", "collection": "authors", "collection_id": "wm81w-wgx51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101105-135833649", "type": "book_section", "title": "Effective Sensor Scheduling Schemes in a Sensor Network by\n Employing Feedback in the Communication Loop", "book_title": "2007 IEEE International Conference on Control Applications", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Sinopoli", "given_name": "Bruno", "clpid": "Sinopoli-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider a state estimation problem over a bandwidth limited network. A sensor network consisting of N sensors is used to observe the states of M plants, but only p \u2264 N sensors can transmit their measurements to a centralized estimator at each time. Therefore a suitable scheme that schedules the proper sensors to access the network at each time so that the total estimation error is minimized is required. We propose four different sensor scheduling schemes. The static and stochastic schemes assume no feedback from the estimator to the scheduler, while the two dynamic schemes, Maximum Error First (MEF) and Maximum Deduction First (MDF) assume such feedback is available. We compare the four schemes via some examples and show MEF and MDF schemes perform better than the static and stochastic schemes, which demonstrates that feedback can play an important role in this remote state estimation problem. We also show that MDF performs better than MEF as MDF considers the total estimation error while MEF considers the individual estimation error.", "doi": "10.1109/CCA.2007.4389365", "isbn": "978-1-4244-0440-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-10", "pages": "1006-1011" }, { "id": "authors:35g6h-68711", "collection": "authors", "collection_id": "35g6h-68711", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101015-111038468", "type": "book_section", "title": "Kalman Filtering with Uncertain Process and Measurement Noise\n Covariances with Application to State Estimation in Sensor Networks", "book_title": "2007 IEEE International Conference on Control Applications", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Johansson", "given_name": "Karl Henrik", "clpid": "Johansson-K-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Distributed state estimation under uncertain process\nand measurement noise covariances is considered. An\nalgorithm based on sensor fusion using Kalman filtering is\ninvestigated. It is shown that if the covariances are decomposed into a known nominal covariance plus an uncertainty term, then the uncertainty of the actual estimation error covariance for the Kalman filter grows linearly with the size of the uncertainty term. This result is extended to the sensor fusion scheme to give an upper bound on the actual error covariance for the fused state estimate. Examples are provided to illustrate how the theory can be applied in practice.", "doi": "10.1109/CCA.2007.4389369", "isbn": "978-1-4244-0440-7", "publisher": "IEEE", "publication_date": "2007-10", "pages": "1031-1036" }, { "id": "authors:a7h63-n0272", "collection": "authors", "collection_id": "a7h63-n0272", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DANacc07", "type": "book_section", "title": "Estimation over Communication Networks: Performance Bounds and Achievability Results", "book_title": "American Control Conference (ACC 2007), New York, NY, 11-13 July 2007", "author": [ { "family_name": "Dana", "given_name": "A. F.", "clpid": "Dana-A-F" }, { "family_name": "Gupta", "given_name": "V.", "clpid": "Gupta-V" }, { "family_name": "Hespanha", "given_name": "J. P.", "clpid": "Hespanha-J-P" }, { "family_name": "Hassibi", "given_name": "B.", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper considers the problem of estimation over communication networks. Suppose a sensor is taking measurements of a dynamic process. However the process needs to be estimated at a remote location connected to the sensor through a network of communication links that drop packets stochastically. We provide a framework for computing the optimal performance in the sense of expected error covariance. Using this framework we characterize the dependency of the performance on the topology of the network and the packet dropping process. For independent and memoryless packet dropping processes we find the steady-state error for some classes of networks and obtain lower and upper bounds for the performance of a general network. Finally we find a necessary and sufficient condition for the stability of the estimate error covariance for general networks with spatially correlated and Markov type dropping process. This interesting condition has a max-cut interpretation.", "doi": "10.1109/ACC.2007.4282933", "isbn": "1-4244-0989-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07-30", "pages": "3450-3455" }, { "id": "authors:pj8aj-92n12", "collection": "authors", "collection_id": "pj8aj-92n12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100506-100128102", "type": "book_section", "title": "Biologically Inspired Feedback Design for Drosophila Flight", "book_title": "American Control Conference, 2007. ACC '07", "author": [ { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Waydo", "given_name": "Stephen", "clpid": "Waydo-S" }, { "family_name": "Fuller", "given_name": "Sawyer B.", "clpid": "Fuller-S-B" }, { "family_name": "Dickson", "given_name": "Will", "clpid": "Dickson-W" }, { "family_name": "Straw", "given_name": "Andrew D.", "orcid": "0000-0001-8381-0858", "clpid": "Straw-A-D" }, { "family_name": "Dickinson", "given_name": "Michael H.", "orcid": "0000-0002-8587-9936", "clpid": "Dickinson-M-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We use a biologically motivated model of the Drosophila's flight mechanics and sensor processing to design a feedback control scheme to regulate forward flight. The model used for insect flight is the grand unified fly (GUF) [3] simulation consisting of rigid body kinematics, aerodynamic forces and moments, sensory systems, and a 3D environment model. We seek to design a control algorithm that will convert the sensory signals into proper wing beat commands to regulate forward flight. Modulating the wing beat frequency and mean stroke angle produces changes in the flight envelope. The sensory signals consist of estimates of rotational velocity from the haltere organs and translational velocity estimates from visual elementary motion detectors (EMD's) and matched retinal velocity filters. The controller is designed based on a longitudinal model of the flight dynamics. Feedforward commands are generated based on a desired forward velocity. The dynamics are linearized around this operating point and a feedback controller designed to correct deviations from the operating point. The control algorithm is implemented in the GUF simulator and achieves the desired tracking of the forward reference velocities and exhibits biologically realistic responses.", "doi": "10.1109/ACC.2007.4282971", "isbn": "1-4244-0988-8", "publisher": "IEEE", "place_of_publication": "New York, NY", "publication_date": "2007-07", "pages": "3395-3401" }, { "id": "authors:n7m3j-ya748", "collection": "authors", "collection_id": "n7m3j-ya748", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101015-111128782", "type": "book_section", "title": "Frequency-Weighted Model Reduction with Applications to Structured Models", "book_title": "American Control Conference 2007", "author": [ { "family_name": "Sandberg", "given_name": "Henrik", "clpid": "Sandberg-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, a frequency-weighted extension of a\nrecently proposed model reduction method for linear systems\nis presented. The method uses convex optimization and can be\nused both with sample data and exact models. We also obtain\nbounds on the frequency-weighted error. The method is combined\nwith a rank-minimization heuristic to approximate multiinput\u2013\nmulti-output systems.We also present two applications\u2014\nenvironment compensation and simplification of interconnected\nmodels \u2014 where we argue the proposed methods are useful.", "doi": "10.1109/ACC.2007.4282746", "isbn": "978-1-4244-0988-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07", "pages": "941-946" }, { "id": "authors:d1jhb-br618", "collection": "authors", "collection_id": "d1jhb-br618", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170427-143640907", "type": "book_section", "title": "Estimation for Nonlinear Dynamical Systems over Packet-Dropping Networks", "book_title": "2007 American Control Conference", "author": [ { "family_name": "Jin", "given_name": "Zhipu", "clpid": "Jin-Zhipu" }, { "family_name": "Ko", "given_name": "Chih-Kai", "clpid": "Ko-Chih-Kai" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Two approaches, extended Kalman filter (EKF) and moving horizon estimation (MHE), are discussed for state estimation for nonlinear dynamical systems over packet-dropping networks. For EKF, we provide sufficient conditions that guarantee a bounded EKF error covariance. For MHE, a natural scheme on organizing the finite horizon window is proposed to handle intermittent observations. A nonlinear programming software package, SNOPT, is employed in MHE and the formulation for constraints is discussed in detail. Examples and simulation results are presented.", "doi": "10.1109/ACC.2007.4283063", "isbn": "1-4244-0988-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07", "pages": "5037-5042" }, { "id": "authors:xf23x-sq947", "collection": "authors", "collection_id": "xf23x-sq947", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150331-142947811", "type": "book_section", "title": "Control Over a Network: Using Actuation Buffers to Reduce Transmission Frequency", "book_title": "2007 European Control Conference (ECC)", "author": [ { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-Ling" }, { "family_name": "Di Cairano", "given_name": "Stefano", "clpid": "Di-Cairano-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We consider a discrete time linear feedback control system with additive noise where the control signals are sent across a network from the controller to the actuators. Due to network considerations it is desired to reduce the transmission frequency of the control signals. We show that by including a finite sequence of predicted control signals in each communication packet the frequency of transmission can be reduced by transmitting only when the previously sent sequence has run out, although as a consequence the closed loop error will increase. We introduce a communication protocol, which we call Input Difference Transmission Scheme (IDTS), that transmits control packets when the difference between newly computed control values and the predicted control sequence previously transmitted is larger than a certain threshold. This threshold is a design parameter and we show how the closed loop behavior varies with this threshold. Simulation results are provided to augment the theory.", "doi": "10.23919/ECC.2007.7068661", "isbn": "978-3-9524173-8-6", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07", "pages": "597-602" }, { "id": "authors:b9qam-5mp43", "collection": "authors", "collection_id": "b9qam-5mp43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100827-104901767", "type": "book_section", "title": "A Multi-Model Approach to Identification of Biosynthetic Pathways", "book_title": "American Control Conference, 2007. ACC '07", "author": [ { "family_name": "Dunlop", "given_name": "Mary J.", "clpid": "Dunlop-M-J" }, { "family_name": "Franco", "given_name": "Elisa", "orcid": "0000-0003-1103-2668", "clpid": "Franco-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We present an identification framework for biochemical systems that allows multiple candidate models to be compared. This framework is designed to select a model that fits the data while maintaining model simplicity. The model identification task is divided into a parameter estimation stage and a model comparison stage. Model selection is based on calculating Akaike's information criterion, which is a systematic method for determining the model that best represents a set of experimental data. Two case studies are presented: a simulated transcriptional control circuit and a system of oscillators that has been built and characterized in vitro. In both examples the multi-model framework is able to discriminate between model candidates to select the one that best describes the data.", "doi": "10.1109/ACC.2007.4282720", "isbn": "1-4244-0988-8", "publisher": "IEEE", "place_of_publication": "New York, NY", "publication_date": "2007-07", "pages": "1600-1605" }, { "id": "authors:zdsv6-qc182", "collection": "authors", "collection_id": "zdsv6-qc182", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170420-134616638", "type": "book_section", "title": "Analysis of a Digital Clock for Molecular Computing", "book_title": "2007 American Control Conference", "author": [ { "family_name": "Ugander", "given_name": "Johan", "clpid": "Ugander-J" }, { "family_name": "Dunlop", "given_name": "Mary J.", "clpid": "Dunlop-M-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The control of synthetic genetic regulatory networks is an emerging engineering challenge. In this study, we propose a new synthetic genetic network that behaves as a digital clock, producing square waveform oscillations. We analyze two models of the network: a deterministic model based on Michaelis-Menten kinetics, as well as a stochastic model based on the Gillespie algorithm. Both models predict regions of oscillatory behavior; the deterministic model provides insight into the conditions required to produce the oscillating clock-like behavior, while the stochastic model is truer to natural dynamics. Intracellular stochasticity is seen to contribute phase noise to the oscillator, and we propose improvements for the network and discuss the conceptual foundations of these improvements.", "doi": "10.1109/ACC.2007.4282583", "isbn": "1-4244-0988-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07", "pages": "1595-1599" }, { "id": "authors:zfrny-1v790", "collection": "authors", "collection_id": "zfrny-1v790", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170426-174355371", "type": "book_section", "title": "To Drop or Not to Drop: Receiver Design Principles for Estimation over Wireless Links", "book_title": "2007 American Control Conference", "author": [ { "family_name": "Mostofi", "given_name": "Yasamin", "clpid": "Mostofi-Y" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we consider estimation of a multiple-input multiple-output dynamical system over a wireless fading communication channel using a Kalman filter. We are interested in finding the optimum receiver design in terms of handing noisy samples. We reformulate the estimation problem to include the impact of stochastic communication noise in the noisy packets. We will show how the eigenvalues of the state transition matrix A affect the optimum receiver design. We prove that, in the absence of a cross-layer information path, packet drop should be designed to balance information loss and communication noise in order to optimize the performance. In the presence of a cross-layer path, we show that keeping all the packets will minimize the average estimation error covariance. We also derive the stability condition in the presence of noisy packets and prove that it is independent of the shape of the communication noise variance or availability of a cross-layer information path.", "doi": "10.1109/ACC.2007.4282593", "isbn": "1-4244-0988-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2007-07", "pages": "2762-2768" }, { "id": "authors:yte6k-tjg27", "collection": "authors", "collection_id": "yte6k-tjg27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200429-082712784", "type": "book_section", "title": "Verification Procedure for Generalized Goal-based Control Programs", "book_title": "AIAA Infotech@Aerospace 2007 Conference and Exhibit", "author": [ { "family_name": "Braman", "given_name": "Julia M. B.", "clpid": "Braman-J-M-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Ingham", "given_name": "Michel D.", "clpid": "Ingham-M-D" } ], "abstract": "Safety verification of fault-tolerant control systems is essential for the success of autonomous robotic systems. A control architecture called Mission Data System, developed at the Jet Propulsion Laboratory, takes a goal-based control approach. In this paper, the development of a method for converting a goal network control program into a hybrid system is given and a process for converting logic associated with the goal network into transition conditions for the hybrid automata is developed. The resulting hybrid system can then be verified for safety in the presence or failures using existing symbolic model checkers. An example task and goal network is designed, converted to hybrid automata, and verified using symbolic model checking software for hybrid systems.", "doi": "10.2514/6.2007-3010", "isbn": "978-1-62410-017-8", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2007-05-07", "pages": "Art. No. 2007-3010" }, { "id": "authors:2tygx-7h647", "collection": "authors", "collection_id": "2tygx-7h647", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170516-160431062", "type": "book_section", "title": "On the robustness of distributed algorithms", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Langbort", "given_name": "Cedric", "clpid": "Langbort-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In recent years, numerous distributed algorithms have been proposed which, when executed by a team of dynamic agents, result in the completion of a joint task. However, for any such algorithm to be practical, one should be able to guarantee that the task is still satisfactorily executed even when agents fail to communicate with others or to perform their designated actions correctly. In this paper, we present a concept of robustness which is well-suited for general distributed algorithms for teams of dynamic agents. Our definition extends a similar notion introduced in the distributed computation literature for consensus problems. We illustrate the definition by considering a variety of algorithms.", "doi": "10.1109/CDC.2006.377451", "isbn": "1-4244-0171-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-12", "pages": "3473-3478" }, { "id": "authors:a1wc3-sxr36", "collection": "authors", "collection_id": "a1wc3-sxr36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170516-161356985", "type": "book_section", "title": "On Sensor Coverage by Mobile Sensors", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Jeffcoat", "given_name": "David E.", "clpid": "Jeffcoat-D-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We study the problem of using a small number of mobile sensors to monitor various threats in a geographical area. Using some recent results on stochastic sensor scheduling, we propose a stochastic sensor movement strategy. We present simple conditions under which it is not possible to maintain a bounded estimate error covariance for all the threats. We also study a simple sub-optimal algorithm to generate stochastic trajectories. Simulations are presented to illustrate the results.", "doi": "10.1109/CDC.2006.377220", "isbn": "1-4244-0171-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-12", "pages": "5912-5917" }, { "id": "authors:sserq-1s660", "collection": "authors", "collection_id": "sserq-1s660", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170516-165501295", "type": "book_section", "title": "Distributed Sensing and Estimation Under Communication Constraints", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Mostofi", "given_name": "Yasamin", "clpid": "Mostofi-Y" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we consider the impact of imperfect communication links on distributed sensing and estimation in mobile networks. First we find optimum sensing regions and sensor positions under communication constraints. We show that the optimum sensor configuration consists of overlapping sensing regions. We then show how the nodes can achieve the optimum configuration in a distributed manner.", "doi": "10.1109/CDC.2006.376939", "isbn": "1-4244-0171-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-12", "pages": "1013-1018" }, { "id": "authors:vwspg-f5d57", "collection": "authors", "collection_id": "vwspg-f5d57", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GUPacc06", "type": "book_section", "title": "On the effect of quantization on performance at high rates", "book_title": "American Control Conference (ACC 2006), Minneapolis, MN, 14-16 June 2006", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Dana", "given_name": "Amir F.", "clpid": "Dana-A-F" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" } ], "abstract": "We study the effect of quantization on the performance of a scalar dynamical system in the high rate regime. We evaluate the LQ cost for two commonly used quantizers: uniform and logarithmic and provide a lower bound on performance of any centroid-based quantizer based on entropy arguments. We also consider the case when the channel drops data packets stochastically.", "doi": "10.1109/ACC.2006.1656407", "isbn": "1-4244-0210-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-07-24", "pages": "1364-1369" }, { "id": "authors:pkjv2-c9k76", "collection": "authors", "collection_id": "pkjv2-c9k76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110209-135047997", "type": "book_section", "title": "Model-based estimation of off-highway road geometry using single-axis LADAR and inertial sensing", "book_title": "Proceedings 2006 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Cremean", "given_name": "Lars B.", "clpid": "Cremean-L-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper applies some previously studied extended\nKalman filter techniques for planar road geometry estimation\nto the domain of autonomous navigation of off-highway\nvehicles. In this work, a clothoid model of the road geometry is\nconstructed and estimated recursively based on road features\nextracted from single-axis LADAR range measurements. We\npresent a method for feature extraction of the road centerline\nin the image plane, and describe its application to recursive\nestimation of the road geometry. We analyze the performance of\nour method against simulated motion of varied road geometries\nand against closed-loop detection, tracking and following of\ndesert roads. Our method accomodates full 6 DOF motion of\nthe vehicle as it navigates, constructs consistent estimates of the\nroad geometry with respect to a fixed global reference frame,\nand requires an estimate of the sensor pose for each range\nmeasurement.", "doi": "10.1109/ROBOT.2006.1641945", "isbn": "0-7803-9505-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-06-26", "pages": "1661-1666" }, { "id": "authors:w303c-z5n22", "collection": "authors", "collection_id": "w303c-z5n22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110203-083444872", "type": "book_section", "title": "A decentralized motion coordination strategy for dynamic target tracking", "book_title": "Proceedings 2006 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Chung", "given_name": "Timothy H.", "clpid": "Chung-Timothy-H" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper presents a decentralized motion planning\nalgorithm for the distributed sensing of a noisy dynamical\nprocess by multiple cooperating mobile sensor agents. This\nproblem is motivated by localization and tracking tasks of\ndynamic targets. Our gradient-descent method is based on a\ncost function that measures the overall quality of sensing. We\nalso investigate the role of imperfect communication between\nsensor agents in this framework, and examine the trade-offs in\nperformance between sensing and communication. Simulations\nillustrate the basic characteristics of the algorithms.", "doi": "10.1109/ROBOT.2006.1642064", "isbn": "0-7803-9505-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006-05", "pages": "2416-2422" }, { "id": "authors:vbcph-3a988", "collection": "authors", "collection_id": "vbcph-3a988", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110225-084451186", "type": "book_section", "title": "Multi-Hop Relay Protocols for Fast Consensus Seeking", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Jin", "given_name": "Zhipu", "clpid": "Jin-Z" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Consensus protocols are distributed algorithms in\nnetworked multi-agent systems. Based on the local information,\nagents automatically converge to a common consensus state\nand the convergence speed is determined by the algebraic\nconnectivity of the communication network. In order to achieve\na fast consensus seeking, we propose the multi-hop relay\nprotocols, where each agent can expand its knowledge by\nemploying multi-hop paths in the network.We demonstrate that\nmulti-hop relay protocols can enlarge the algebraic connectivity\nwithout physically changing the network topology. Moreover,\ncommunication delays are discussed and a tradeoff is identified\nbetween the convergence speed and the time delay sensitivity.", "doi": "10.1109/CDC.2006.377298", "isbn": "1-4244-0171-2", "publisher": "IEEE", "place_of_publication": "Piscataway, N.J.", "publication_date": "2006", "pages": "1001-1006" }, { "id": "authors:82yvb-x8n64", "collection": "authors", "collection_id": "82yvb-x8n64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110629-092232291", "type": "book_section", "title": "Dynamic Sensor Coverage with Uncertainty Feedback : Analysis Using Iterated Maps", "book_title": "Proceedings of the 2006 American Control Conference", "author": [ { "family_name": "Tiwari", "given_name": "Abhishek", "clpid": "Tiwari-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper presents an analysis of the dynamic\nsensor coverage problem with uncertainty feedback. We consider a simple case of two spatially separate uncertain systems 1 and 2. In an earlier paper we introduced the dynamic sensor coverage problem and gave two stochastic sensor motion algorithms to solve the problem. We take a deterministic approach in this paper, the sensor decides to measure system 1 or 2 based on the relative uncertainty of its estimates of the states of the two systems. Error covariance is used as a metric\nfor uncertainty of estimates. Based on the sensor measurements\nthe error covariance evolves according to the Lyapunov or the\nRiccati map. The uncertainty space is partitioned and each\npartition has a different sensor motion decision associated with\nit. For a certain class of partitions we prove the existence\nand local stability of a unique periodic steady state orbit. We\nprove global stability for a scalar special case. We also show\nby way of an example that by changing certain parameters in\nthese partitions stable orbits of higher periods can be obtained.\nImplications of this work and comparisons with existing work\nin the sensor scheduling and sensor coverage literature are\nalso presented. In the end we present a discussion on future\nextensions of this work. Simulation examples are provided to\nillustrate the main concepts.", "doi": "10.1109/ACC.2006.1657671", "isbn": "1-4244-0209-3", "publisher": "IEEE", "place_of_publication": "New York, NY", "publication_date": "2006", "pages": "5929-5934" }, { "id": "authors:ty67t-0pv17", "collection": "authors", "collection_id": "ty67t-0pv17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110203-112414637", "type": "book_section", "title": "An Estimation Algorithm for a Class of Networked Control Systems Using UDP-Like Communication Schemes", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this work we consider a class of networked control systems (NCS) when the control signal is sent to the plant via a UDP-like communication protocol. In this case the controller sends a communication packet to the plant across a lossy network, but the controller does not receive any acknowledgement signal indicating the status of the control packet. Standard observer based estimators assume the estimator has knowledge of what control signal is applied to the plant. Under the UDP-like protocol the controller/estimator does not have explicit knowledge whether the control signals have been applied to the plant or not. We present a simple estimation and control algorithm that consists of a state and mode observer as well as a constraint on the control signal sent to the plant. For the class of systems considered, discrete time LTI plants where at least one of the states that is directly affected by the input is also part of the measurement vector, the estimator is able to recover the fate of the control packet from the measurement at the next timestep and exhibit better performance than other naive schemes. For single-input-single-output (SISO) systems we are able to show convergence properties of the estimation error and closed loop stability. Simulations are provided to demonstrate the algorithm and show its effectiveness.", "doi": "10.1109/CDC.2006.377481", "isbn": "978-1-4244-0170-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006", "pages": "5597-5603" }, { "id": "authors:q5ffq-d8975", "collection": "authors", "collection_id": "q5ffq-d8975", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110720-090204055", "type": "book_section", "title": "Networked control systems with norm bounded uncertainties: a stability analysis", "book_title": "Proceedings of the 2006 American Control Conference", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider a robust networked\ncontrol problem. We consider linear unstable and uncertain\ndiscrete time plants with networks between the sensors and\ncontroller as well as the controller and plant. We investigate\ntwo defining characteristics of networked control systems and\nthe impact uncertainty has on these. Namely, the minimum data\nrates required for the two networks and the tolerable data drop\nout in the form of packet losses. We are able to derive sufficient\nconditions in terms of the minimum data rate and minimum\npacket arrival rate to ensure stability of the closed loop system.", "doi": "10.1109/ACC.2006.1656645", "isbn": "1-4244-0209-3", "publisher": "IEEE", "place_of_publication": "New York", "publication_date": "2006", "pages": "2783-2788" }, { "id": "authors:ghj29-acz31", "collection": "authors", "collection_id": "ghj29-acz31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110707-134914811", "type": "book_section", "title": "Distributed Control over Failing Channels", "book_title": "Networked Embedded Sensing and Control", "author": [ { "family_name": "Langbort", "given_name": "C\u00e9dric", "clpid": "Langbort-C" }, { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Antsaklis", "given_name": "P. J.", "clpid": "Antsaklis-P-J" }, { "family_name": "Tabuada", "given_name": "P.", "clpid": "Tabuada-P" } ], "abstract": "We give sufficient convex conditions for the existence of a distributed controller, with the same interconnection structure as the plant, when the latter is composed of heterogeneous subsystems that communicate with their neighbors over packet-dropping channels. Our linear matrix inequalities generalize previous results for the case of ideal communication links and, although conservative, are typically far more tractable for large-scale systems than recently obtained sufficient and necessary conditions.", "doi": "10.1007/11533382_22", "isbn": "3-540-32794-0", "publisher": "Springer", "place_of_publication": "New York", "publication_date": "2006", "pages": "325-342" }, { "id": "authors:gf9ym-tbh42", "collection": "authors", "collection_id": "gf9ym-tbh42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110720-075738157", "type": "book_section", "title": "Optimum Allocation of Computing Resources in\n Networked Sensing and Control", "book_title": "Proceedings of the 2006 American Control Conference", "author": [ { "family_name": "Mostofi", "given_name": "Yasamin", "clpid": "Mostofi-Y" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we consider task scheduling when\nsensing and controlling over a network with packet dropping\nlinks. We find optimum ways of allocating limited computing\nresources for estimation and control of a number of linear\ndynamical systems with different characteristics over communication\nlinks with different qualities. We find theoretical\nexpressions relating the optimum sampling rates of the dynamical\nsystems to the characteristics of the communication links\nand dynamics of the plants. We derive optimum ways of task\nscheduling for two performance metrics: decay rate and the\nasymptotic value. The work lays the theoretical foundations\nfor considering the impact of both limited computing and\ncommunication resources on estimation and control.", "doi": "10.1109/ACC.2006.1657261", "isbn": "1-4244-0209-3", "publisher": "IEEE", "place_of_publication": "New York", "publication_date": "2006", "pages": "3507-3512" }, { "id": "authors:r3yjh-1jq87", "collection": "authors", "collection_id": "r3yjh-1jq87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110803-093845327", "type": "book_section", "title": "Towards a Packet-based Control Theory - Part II: Rate Issues", "book_title": "2006 American Control Conference", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Following our first paper of stabilizing a Linear\nTime Invariant (LTI) system in a packet-based network, which\nappeared in ACC 05, this paper further studies various rate\nissues associated with networked control systems. Specifically, networks with finite bandwidth and packet drops and systems with finite control inputs are studied in detail. Similar to what we did in the previous paper, we assume that the state information is transmitted to the controller over a packet-based network. We also assume that there is a perfect link from the controller to the plant. However, we change the notion of the system being asymptotically stable to almost sure stable which is in a probabilistic framework. This is because packet drops by the network introduce unavoidable randomness. With\nthe notion of almost sure stability, various rate results under different settings are given. Examples and simulations are provided to demonstrate the results.", "doi": "10.1109/ACC.2006.1657257", "isbn": "1-4244-0209-3", "publisher": "IEEE", "place_of_publication": "New York, NY", "publication_date": "2006", "pages": "3482-3487" }, { "id": "authors:vjdfm-ztk86", "collection": "authors", "collection_id": "vjdfm-ztk86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110615-112206500", "type": "book_section", "title": "The Effect of Sensor Health on State Estimation", "book_title": "Proceedings of the 45th IEEE Conference on Decision and Control", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the problem of state\nestimation using the standard Kalman filter recursions which\ntakes account of the available sensor health information. Given\na stochastic description of the sensor health, we are able\nto show that the expected error covariance converges to a\nunique value for all initial values, while the available previous\nwork only showed the upper bound of the expected error\ncovariance converges. Our approach provides both theoretical\nvalue to the analysis as well as the potential to get tighter\nupper bound. Our results provide a criterion of evaluating\nthe sensor measurement. In the multisensor fusion problem,\ndepending on the system error tolerance levels, it can then be\ndetermined whether to fuse a particular sensor measurement\nor not. Examples and simulations are provided to assist the\ntheory.", "doi": "10.1109/CDC.2006.377482", "isbn": "978-1-4244-0170-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2006", "pages": "3315-3320" }, { "id": "authors:4yh97-6b303", "collection": "authors", "collection_id": "4yh97-6b303", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170517-164222886", "type": "book_section", "title": "Distributed Averaging on Asynchronous Communication Networks", "book_title": "Proceedings of the 44th IEEE Conference on Decision and Control", "author": [ { "family_name": "Mehyar", "given_name": "Mortada", "clpid": "Mehyar-M" }, { "family_name": "Spanos", "given_name": "Demetri", "clpid": "Spanos-D-P" }, { "family_name": "Pongsajapan", "given_name": "John", "clpid": "Pongsajapan-J" }, { "family_name": "Low", "given_name": "Steven H.", "orcid": "0000-0001-6476-3048", "clpid": "Low-S-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Distributed algorithms for averaging have attracted interest in the control and sensing literature. However, previous works have not addressed some practical concerns that will arise in actual implementations on packet-switched communication networks such as the Internet. In this paper, we present several implementable algorithms that are robust to asynchronism and dynamic topology changes. The algorithms do not require global coordination and can be proven to converge under very general asynchronous timing assumptions. Our results are verified by both simulation and experiments on a real-world TCP/IP network.", "doi": "10.1109/CDC.2005.1583363", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "7446-7451" }, { "id": "authors:nz65n-12k40", "collection": "authors", "collection_id": "nz65n-12k40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110818-111717130", "type": "book_section", "title": "State estimation utilizing multiple description coding over lossy networks", "book_title": "2005 44th IEEE Conference on Decision and Control & European Control Conference", "author": [ { "family_name": "Jin", "given_name": "Zhipu", "clpid": "Jin-Zhipu" }, { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "For state estimation in networked control systems,\nthe impact of packet dropping over network links is an important problem. In this paper, we introduce multiple description (MD) source coding scheme to improve the statistical stability and performance of the estimation error covariance of Kalman filter with packet loss. We consider about two cases: when the packet loss over network links occurs in an i.i.d. fashion or in a bursty fashion. Compared with the traditional single description source coding, MD coding scheme can greatly improve the\nperformance of Kalman filter over a large set of packet loss\nscenarios in both cases.", "doi": "10.1109/CDC.2005.1582267", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "872-878" }, { "id": "authors:wp4p6-drp43", "collection": "authors", "collection_id": "wp4p6-drp43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110825-140024412", "type": "book_section", "title": "Estimation with Information Loss: Asymptotic Analysis and Error Bounds", "book_title": "2005 44th IEEE Conference on Decision and Control & European Control Conference", "author": [ { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Tiwari", "given_name": "Abhishek", "clpid": "Tiwari-A" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider a discrete time state estimation problem over a packet-based network. In each discrete time step, the measurement is sent to a Kalman filter with some probability that it is received or dropped. Previous pioneering work on Kalman filtering with intermittent observation losses shows that there exists a certain threshold of the packet dropping rate below which the estimator is stable in the expected sense. That work assumes that packets are dropped independently between all time steps. However we give a completely different point of view. On the one hand, it is not required that the packets are dropped independently but just that the information gain \u03c0_g, defined to be the limit of the ratio of the number of received packets n during N time steps as N goes to infinity, exists. On the other hand, we show that for any given \u03c0g, as long as \u03c0_g> 0, the estimator is stable almost surely, i.e. for any given \u03b5 > 0, the error covariance matrix P_k is bounded by a finite matrix M, with probability 1 -\u03b5. We also give explicit formula for the relationship between M and \u03b5. We consider the case where the observation matrix is invertible.", "doi": "10.1109/CDC.2005.1582324", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "1215-1221" }, { "id": "authors:r1c0j-4yr78", "collection": "authors", "collection_id": "r1c0j-4yr78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-155010781", "type": "book_section", "title": "A Control-Oriented Analysis of Bio-inspired Visuomotor Convergence", "book_title": "44th IEEE Conference on Decision and Control", "author": [ { "family_name": "Humbert", "given_name": "J. Sean", "clpid": "Humbert-J-S" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Dickinson", "given_name": "Michael H.", "orcid": "0000-0002-8587-9936", "clpid": "Dickinson-M-H" } ], "abstract": "Insects exhibit incredibly robust closed loop fight dynamics in the face of uncertainties. A fundamental principle contributing to this unparalleled behavior is rapid processing and convergence of visual sensory information to fight motor commands via spatial wide-field integration, accomplished by retinal motion pattern sensitive interneurons (LPTCs) in the lobula plate portion of the visual ganglia. With in a control- theoretic frame work, models for spatially continuous retinal image flow and wide-field integration processing are developed, establishing the connection between image flow kernels (retinal motion pattern sensitivities) and the feedback terms they represent. It is shown that these out puts are sufficient to stabilize speed regulation and terrain following tasks. Hence, extraction of global retinal motion cues through computationally efficient wide-field integration processing provides a novel and promising methodology for utilizing visual sensory information in autonomous robotic navigation and fight control applications.", "doi": "10.1109/CDC.2005.1582162", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "245-250" }, { "id": "authors:5hdpq-54347", "collection": "authors", "collection_id": "5hdpq-54347", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110817-110410615", "type": "book_section", "title": "On Sensor Fusion in the Presence of Packet-dropping Communication Channels", "book_title": "2005 44th IEEE Conference on Decision and Control & European Control Conference", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we look at the problem of multisensor data fusion when data is being communicated over channels that drop packets randomly. We are motivated by the use of wireless links for communication among nodes in upcoming sensor networks. We wish to identify the information that should be communicated by each node to others given that some of the information it had transmitted earlier might have been lost. We solve the problem exactly for the case of two sensors and study the performance of the algorithm when more sensors are present. For the two-sensor case, the performance of our algorithm is optimal in the sense that if a packet is received from the other sensor, it is equivalent to receiving all previous measurements, irrespective of the packet drop pattern.", "doi": "10.1109/CDC.2005.1582712", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "3547-3552" }, { "id": "authors:3kcrp-ge931", "collection": "authors", "collection_id": "3kcrp-ge931", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110822-085321885", "type": "book_section", "title": "Receiver Design Principles for Estimation over Fading Channels", "book_title": "2005 44th IEEE Conference on Decision and Control & European Control Conference", "author": [ { "family_name": "Mostofi", "given_name": "Yasamin", "clpid": "Mostofi-Y" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we consider estimation of dynamical\nsystems over wireless communication channels. We show\nthat the communication protocols suitable for non real-time\napplications like data networks may not be entirely applicable for estimation and control of a rapidly changing dynamical system. We then develop new design paradigms for these applications to show how noisy packets should be handled in the receiver. We prove that, in the presence of a crosslayer feedback, keeping all the packets will both maximize the stability range and minimize the estimation error variance. In the absence of such a feedback, we show that keeping all the packets still maximizes the stability range, independent of the shape of the communication noise profile. In order to optimize the performance, in the absence of a cross-layer feedback, we prove that packet drop should be designed to balance information loss and communication noise.", "doi": "10.1109/CDC.2005.1582199", "isbn": "0-7803-9567-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-12", "pages": "464-469" }, { "id": "authors:s13fp-hdz90", "collection": "authors", "collection_id": "s13fp-hdz90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130703-133331635", "type": "book_section", "title": "Estimation of linear stochastic systems over a queueing network", "book_title": "2005 Systems Communications, Proceedings", "author": [ { "family_name": "Epstein", "given_name": "Michael", "clpid": "Epstein-M" }, { "family_name": "Tiwari", "given_name": "Abhishek", "clpid": "Tiwari-A" }, { "family_name": "Shi", "given_name": "Ling", "clpid": "Shi-L" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the standard state estimation problem over a congested packet-based network. The network is modeled as a queue with a single server processing the packets. This provides a framework to consider the effect of packet drops, packet delays and bursty losses on state estimation. We use a modified Kalman Filter with buffer to cope with delayed packets. We analyze the stability of the estimates with varying buffer length and queue size. We use high order Markov chains for our analysis. Simulation examples are presented to illustrate the theory.", "doi": "10.1109/ICW.2005.46", "isbn": "0-7695-2422-2", "publisher": "IEEE Computer Society", "place_of_publication": "Los Alamitos, CA", "publication_date": "2005-08", "pages": "389-394" }, { "id": "authors:etf17-73312", "collection": "authors", "collection_id": "etf17-73312", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150210-072226646", "type": "book_section", "title": "On LQG control across a stochastic packet-dropping link", "book_title": "Proceedings of the 2005 American Control Conference", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Spanos", "given_name": "Demetri", "clpid": "Spanos-D-P" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the problem of\noptimal Linear Quadratic Gaussian control of a system\nin which communication between the sensor and the\ncontroller occurs across a packet-dropping link. We first\nprove a separation principle that allows us to solve this\nproblem using a standard LQR state-feedback design,\nalong with an optimal algorithm for propagating and\nusing the information across the unreliable link. Then\nwe present one such optimal algorithm, which consists\nof a Kalman filter at the sensor side of the link, and a\nswitched linear filter at the controller side. Our design\ndoes not assume any statistical model of the packet drop\nevents, and is thus optimal for any arbitrary packet\ndrop pattern. Further, the solution is appealing from a\npractical point of view because it can be implemented as\na small modification of an existing LQG control design.", "doi": "10.1109/ACC.2005.1469960", "isbn": "0-7803-9098-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-06", "pages": "360-365" }, { "id": "authors:58zas-knn35", "collection": "authors", "collection_id": "58zas-knn35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:SPAipsn05", "type": "book_section", "title": "Approximate distributed Kalman filtering in sensor networks with quantifiable performance", "book_title": "Fourth International Symposium on Information Processing in Sensor Networks, 2005 (IPSN 2005)", "author": [ { "family_name": "Spanos", "given_name": "Demetri P.", "clpid": "Spanos-D-P" }, { "family_name": "Olfati-Saber", "given_name": "Reza", "clpid": "Olfati-Saber-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We analyze the performance of an approximate distributed Kalman filter proposed in recent work on distributed coordination. This approach to distributed estimation is novel in that it admits a systematic analysis of its performance as various network quantities such as connection density, topology, and bandwidth are varied. Our main contribution is a frequency-domain characterization of the distributed estimator's steady-state performance; this is quantified in terms of a special matrix associated with the connection topology called the graph Laplacian, and also the rate of message exchange between immediate neighbors in the communication network.", "doi": "10.1109/IPSN.2005.1440912", "isbn": "0-7803-9201-9", "publisher": "IEEE", "place_of_publication": "Los Alamitos, CA", "publication_date": "2005-04-15", "pages": "133-139" }, { "id": "authors:zx30k-y0y67", "collection": "authors", "collection_id": "zx30k-y0y67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110811-104030081", "type": "book_section", "title": "An Experimental Platform for Motion Estimation and\n Maneuver Characterization in High Speed Off-Road Driving", "book_title": "Proceedings of the 2005 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Huang", "given_name": "Haomiao", "clpid": "Huang-H" }, { "family_name": "Chamberlain", "given_name": "Lyle", "clpid": "Chamberlain-L" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes a low-cost experimental platform for investigating control and dynamics of a vehicle performing high speed sliding turns in an off-road environment. The hardware design and field performance of the vehicle are discussed. State and control input data were recorded during a series of human-controlled off-road driving maneuvers. Analysis performed on the data demonstrates the ability to detect slippage and measure sideslip angle. Preliminary classification of human control inputs using pattern recognition techniques shows the ability to match steering inputs with vehicle trajectories that can be used to develop motion primitives for vehicle control. These tools and techniques will be used for the development of high speed autonomous off-road driving.", "doi": "10.1109/ROBOT.2005.1570585", "isbn": "0-7803-8914-X", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-04", "pages": "3090-3095" }, { "id": "authors:2y774-3te25", "collection": "authors", "collection_id": "2y774-3te25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161201-132855346", "type": "book_section", "title": "Communication and sensing trade-offs in decentralized mobile sensor networks: a cross-layer design approach", "book_title": "IPSN 2005. Fourth International Symposium on Information Processing in Sensor Networks, 2005", "author": [ { "family_name": "Mostofi", "given_name": "Yasamin", "clpid": "Mostofi-Y" }, { "family_name": "Chung", "given_name": "Timothy H.", "clpid": "Chung-Timothy-H" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" } ], "abstract": "In this paper we characterize the impact of imperfect communication on the performance of a decentralized mobile sensor network. We first examine and demonstrate the trade-offs between communication and sensing objectives, by determining the optimal sensor configurations when introducing imperfect communication. We further illustrate the performance degradation caused by non-ideal communication links in a decentralized mobile sensor network. To address this, we propose a decentralized motion-planning algorithm that considers communication effects. The algorithm is a cross-layer design based on the proper interface of physical and application layers. Simulation results will show the performance improvement attained by utilizing this algorithm.", "doi": "10.1109/IPSN.2005.1440910", "isbn": "0-7803-9201-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-04", "pages": "118-125" }, { "id": "authors:6tvvj-z0f93", "collection": "authors", "collection_id": "6tvvj-z0f93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-072421791", "type": "book_section", "title": "Scheduling for Distributed Sensor Networks with Single Sensor Measurement per Time Step", "book_title": "2004 IEEE International Conference on Robotics and Automation, Proceedings. ICRA '04", "author": [ { "family_name": "Chung", "given_name": "Timothy H.", "clpid": "Chung-Timothy-H" }, { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Burdick", "given_name": "Joel", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We examine the problem of distributed estimation when only one sensor can take a measurement per time step. We solve for the optimal recursive estimation algorithm when the sensor switching schedule is given. We then consider the effect of noise in communication channels. We also investigate the problem of determining an optimal sensor switching strategy. We see that this problem involves searching a tree in general and propose two strategies for pruning the tree to minimize the computation. The first is a sliding window strategy motivated by the Viterbi algorithm, and the second one uses thresholding. The performance of the algorithms is illustrated using numerical examples.", "doi": "10.1109/ROBOT.2004.1307149", "isbn": "0-7803-8232-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2005-04", "pages": "187-192" }, { "id": "authors:3jq7g-yg461", "collection": "authors", "collection_id": "3jq7g-yg461", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170725-125802135", "type": "book_section", "title": "Existence of Cascade Discrete-Continuous State Estimators for Systems on a Partial Order", "book_title": "Hybrid Systems: Computation and Control", "author": [ { "family_name": "Del Vecchio", "given_name": "Domitilla", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Morari", "given_name": "Manfred", "clpid": "Morari-M" }, { "family_name": "Thiele", "given_name": "Lothar", "clpid": "Thiele-L" } ], "abstract": "In this paper, a cascade discrete-continuous state estimator on a partial order is proposed and its existence investigated. The continuous state estimation error is bounded by a monotonically nonincreasing function of the discrete state estimation error, with both the estimation errors converging to zero. This work shows that the lattice approach to estimation is general as the proposed estimator can be constructed for any observable and discrete state observable system. The main advantage of using the lattice approach for estimation becomes clear when the system has monotone properties that can be exploited in the estimator design. In such a case, the computational complexity of the estimator can be drastically reduced and tractability can be achieved. Some examples are proposed to illustrate these ideas.", "doi": "10.1007/978-3-540-31954-2_15", "isbn": "978-3-540-25108-8", "publisher": "Springer", "place_of_publication": "Berlin", "publication_date": "2005-03", "pages": "226-241" }, { "id": "authors:njzp3-m9k38", "collection": "authors", "collection_id": "njzp3-m9k38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190627-094444006", "type": "book_section", "title": "On a decentralized active sensing strategy using mobile sensor platforms in a network", "book_title": "43rd IEEE Conference on Decision and Control", "author": [ { "family_name": "Chung", "given_name": "Timothy H.", "clpid": "Chung-Timothy-H" }, { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the problem of active sensing using mobile nodes as a sensor network to estimate the state of a dynamic target. We propose a gradient-search-based decentralized algorithm that demonstrates the benefits of distributed sensing. We then examine the task of tracking multiple targets, and address it via a simple extension to our algorithm. Simulation results show that our simple decentralized approach performs quite well and leads to interesting cooperative behavior.", "doi": "10.1109/CDC.2004.1430327", "isbn": "0-7803-8682-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2004-12", "pages": "1914-1919" }, { "id": "authors:nv60m-4fn90", "collection": "authors", "collection_id": "nv60m-4fn90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190322-120335030", "type": "book_section", "title": "Vision as a compensatory mechanism for disturbance rejection in upwind flight", "book_title": "Proceedings of the 2004 American Control Conference", "author": [ { "family_name": "Reiser", "given_name": "Michael B.", "clpid": "Reiser-M-B" }, { "family_name": "Humbert", "given_name": "J. Sean", "clpid": "Humbert-J-S" }, { "family_name": "Dunlop", "given_name": "Mary J.", "clpid": "Dunlop-M-J" }, { "family_name": "Del Vecchio", "given_name": "Domitilla", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Dickinson", "given_name": "Michael H.", "orcid": "0000-0002-8587-9936", "clpid": "Dickinson-M-H" } ], "abstract": "Recent experimental results demonstrate that flies possess a robust tendency to orient towards the frontally-centered focus of the visual motion field that typically occurs during upwind flight. We present a closed loop flight model, with a control algorithm based on feedback of the location of the visual focus of contraction, which is affected by changes in wind direction. The feasibility of visually guided upwind orientation is demonstrated with a model derived from current understanding of the biomechanics and sensorimotor computation of insects. The matched filter approach used to model the visual system computations compares extremely well with open-loop experimental data.", "doi": "10.23919/acc.2004.1383623", "isbn": "0780383354", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2004-07", "pages": "311-316" }, { "id": "authors:s5ytf-w0r28", "collection": "authors", "collection_id": "s5ytf-w0r28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-070629438", "type": "book_section", "title": "On the synthesis of control laws for a network of autonomous agents", "book_title": "Proceedings of the 2004 American Control Conference", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We study the synthesis problem of a LQR controller when the matrix describing the control law is additionally constrained to lie in a particular vector space. Our motivation is the use of such control laws to stabilize networks of autonomous agents in a decentralized fashion; with the information flow being dictated by the constraints of a pre-specified topology. We formulate the problem as an optimization problem and provide numerical procedures to solve it. Then, we apply the technique to the decentralized vehicle formation control problem and show that the topology can have a significant effect on the optimal cost.", "isbn": "0-7803-8335-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2004-07", "pages": "4927-4932" }, { "id": "authors:vswwf-tx625", "collection": "authors", "collection_id": "vswwf-tx625", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-071543730", "type": "book_section", "title": "Sensor scheduling algorithms requiring limited computation", "book_title": "IEEE International Conference on Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04)", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Chung", "given_name": "Timothy", "clpid": "Chung-Timothy-H" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we consider the scenario where many sensors co-operate to estimate a process. Only one sensor can take a measurement at any time step. We wish to come up with optimal sensor scheduling algorithms. The problem is motivated by the use of sonar range-finders used by the vehicles on the Caltech Multi-Vehicle Wireless Testbed. We see that this problem involves searching a tree in general and propose and analyze two strategies for pruning the tree to keep the computation limited. The first is a sliding window strategy motivated by the Viterbi algorithm, and the second one uses thresholding. We also study a technique that employs choosing the sensors randomly from a probability distribution which can then be optimized. The performance of the algorithms are illustrated with the help of numerical examples.", "doi": "10.1109/ICASSP.2004.1326672", "isbn": "0-7803-8484-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2004-05", "pages": "825-828" }, { "id": "authors:1y01d-zzv48", "collection": "authors", "collection_id": "1y01d-zzv48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-124740570", "type": "book_section", "title": "Discrete State Estimators for a Class of Hybrid Systems on a Lattice", "book_title": "Hybrid Systems: Computation and Control", "author": [ { "family_name": "Del Vecchio", "given_name": "Domitilla", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "contributor": [ { "family_name": "Alur", "given_name": "Rajeev", "clpid": "Alur-R" }, { "family_name": "Pappas", "given_name": "George J.", "clpid": "Pappas-G-J" } ], "abstract": "In this paper we consider the problem of estimating discrete variables in a class of hybrid systems where we assume that the continuous variables are available for measurement. Using lattice and order theory we develop a frame-work for constructing a discrete state estimator on an enlarged space of variables with lattice structure, which updates only two variables at each step. We apply our ideas to a multi-robot system example, the RoboFlag Drill.", "doi": "10.1007/978-3-540-24743-2_21", "isbn": "9783540212591", "publisher": "Springer", "place_of_publication": "Berlin, Heidelberg", "publication_date": "2004", "pages": "311-325" }, { "id": "authors:yz4wn-e7971", "collection": "authors", "collection_id": "yz4wn-e7971", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150513-085011394", "type": "book_section", "title": "Nonlinear and cooperative control of multiple hovercraft with input constraints", "book_title": "2003 European Control Conference", "author": [ { "family_name": "Dunbar", "given_name": "William B.", "clpid": "Dunbar-W-B" }, { "family_name": "Olfati-Saber", "given_name": "Reza", "clpid": "Olfati-Saber-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we introduce an approach for distributed nonlinear control of multiple hovercraft-type underactuated vehicles with bounded and unidirectional inputs. First, a bounded nonlinear controller is given for stabilization and tracking of a single vehicle, using a cascade backstepping method. Then, this controller is combined with a distributed gradient-based control for multi-vehicle formation stabilization using formation potential functions previously constructed. The vehicles are used in the Caltech Multi-Vehicle Wireless Testbed (MVWT). We provide simulation and experimental results for stabilization and tracking of a single vehicle, and a simulation of stabilization of a six-vehicle formation, demonstrating that in all cases the control bounds and the control objective are satisfied.", "isbn": "978-3-9524173-7-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2003-09", "pages": "1917-1922" }, { "id": "authors:gc44e-ch547", "collection": "authors", "collection_id": "gc44e-ch547", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150513-074656184", "type": "book_section", "title": "Classification of human actions into dynamics based primitives with application to drawing tasks", "book_title": "European Control Conference (ECC 2003)", "author": [ { "family_name": "Del Vecchio", "given_name": "D.", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Perona", "given_name": "P.", "orcid": "0000-0002-7583-5809", "clpid": "Perona-P" } ], "abstract": "We develop the study of primitives of human motion, which we refer to as movemes. The idea is to understand human motion by decomposing it into a sequence of elementary building blocks that belong to a known alphabet of dynamical systems. How can we construct an alphabet of movemes from human data? In this paper we address this issue by introducing the notion of well-posednes. Using examples from human drawing data, we show that the well-posedness notion can be applied in practice so to establish if sets of actions, viewed as signals in time, can define movemes.", "isbn": "978-3-9524173-7-9", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2003-09", "pages": "445-450" }, { "id": "authors:8sffr-adw28", "collection": "authors", "collection_id": "8sffr-adw28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111018-134102626", "type": "book_section", "title": "Segmentation of human motion into dynamics based primitives with application to drawing tasks", "book_title": "Proceedings of the 2003 American Control Conference", "author": [ { "family_name": "Del Vecchio", "given_name": "D.", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Perona", "given_name": "Pietro", "orcid": "0000-0002-7583-5809", "clpid": "Perona-P" } ], "abstract": "Using tools from dynamical systems and systems identification we develop a framework for the study of decomposition of human motion. The objective is understanding human motion by decomposing it into a\nsequence of elementary building blocks, which we refer\nto as movemes, which belong to a known alphabet of\ndynamical systems: We develop classification and segmentation algorithms with error analysis and we test\nthem on human drawing data.", "doi": "10.1109/ACC.2003.1239860", "isbn": "0780378962", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2003-06", "pages": "1816-1823" }, { "id": "authors:c6kgq-jhx19", "collection": "authors", "collection_id": "c6kgq-jhx19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170522-153018041", "type": "book_section", "title": "Consensus protocols for networks of dynamic agents", "book_title": "Proceedings of the 2003 American Control Conference, 2003", "author": [ { "family_name": "Saber", "given_name": "Reza Olfati", "clpid": "Saber-R-O" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper, we introduce linear and nonlinear consensus protocols for networks of dynamic agents that allow the \nagents to agree in a distributed and cooperative fashion. \nWe consider the cases of networks with communication time-delays and channels that have filtering effects. \nWe find a tight upper bound on the maximum fixed time-delay \nthat can be tolerated in the network. It turns out that the \nconnectivity of the network is the key in reaching a \nconsensus. The case of agreement with bounded inputs is \nconsidered by analyzing the convergence of a class of nonlinear protocols. A Lyapunov function is introduced that \nquantifies the total disagreement among the nodes of a \nnetwork. Simulation results are provided for agreement in networks with communication time-delays and constrained inputs.", "doi": "10.1109/ACC.2003.1239709", "isbn": "0-7803-7896-2", "publisher": "IEEE", "place_of_publication": "Piscatway, NJ", "publication_date": "2003-06", "pages": "951-956" }, { "id": "authors:wyqkk-pmv02", "collection": "authors", "collection_id": "wyqkk-pmv02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-075328058", "type": "book_section", "title": "On the control of jump linear Markov systems with Markov state estimation", "book_title": "Proceedings of the 2003 American Control Conference, 2003.", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" } ], "abstract": "We analyze a jump linear Markov system being stabilized using a linear controller. We consider the case when the Markov state is associated with the probability distribution of a measured variable. We assume that the Markov state is not known, but rather is being estimated based on the observations of the variable. We present conditions for the stability of such a system and also solve the optimal LQR control problem for the case when the state estimate update uses only the last observation value. In particular we consider a suboptimal version of the casual Viterbi estimation algorithm and show that a separation property does not hold between the optimal control and the Markov state estimate. Some simple examples are also presented.", "doi": "10.1109/ACC.2003.1243762", "isbn": "0-7803-7896-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2003", "pages": "2893-2898" }, { "id": "authors:tp3v1-zfe08", "collection": "authors", "collection_id": "tp3v1-zfe08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-070320141", "type": "book_section", "title": "Stability analysis of stochastically varying formations of dynamic agents", "book_title": "42nd IEEE Conference on Decision and Control, 2003. Proceedings.", "author": [ { "family_name": "Gupta", "given_name": "Vijay", "clpid": "Gupta-V" }, { "family_name": "Hassibi", "given_name": "Babak", "orcid": "0000-0002-1375-5838", "clpid": "Hassibi-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We analyze a network of dynamic agents where the topology of the network specifies the information flow between the agents. We present an analysis method for such a system for both consensus and formation stabilization problems. To consider the general features introduced by the information flow topology, we consider the case of agent dynamics being a single integrator. Then we show that the method of analysis can be extended to more general cases of complicated agent dynamics, non-ideal links for information flow, etc. We also consider the case when the topology of the network is changing over time. The focus of the paper is on obtaining conditions for the stability of the formation that can be checked in a decentralized way.", "doi": "10.1109/CDC.2003.1272613", "isbn": "0-7803-7924-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2003", "pages": "504-509" }, { "id": "authors:w3btx-2kq60", "collection": "authors", "collection_id": "w3btx-2kq60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190214-123721078", "type": "book_section", "title": "On the choice of norm for modeling compressible flow dynamics at reduced-order using the POD", "book_title": "Proceedings of the 41st IEEE Conference on Decision and Control", "author": [ { "family_name": "Colonius", "given_name": "Tim", "orcid": "0000-0003-0326-3909", "clpid": "Colonius-T" }, { "family_name": "Rowley", "given_name": "Clancy W.", "orcid": "0000-0002-9099-5739", "clpid": "Rowley-C-W" }, { "family_name": "Freund", "given_name": "Jonathan B.", "clpid": "Freund-J-B" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We use POD (proper orthogonal decomposition)/Galerkin projection to investigate and derive reduced-order models of the dynamics of compressible flows. We examine DNS data for two flows, a turbulent M=0.9 jet and self-sustained oscillations in the flow over an open cavity, and show how different choices of norm lead to different definitions of the energetic structures, and, for the cavity, to different reduced-order models of the dynamics. For the jet, we show that the near-field dynamics are fairly well represented by relatively few modes, but that key processes of interest, such as acoustic radiation, are not well captured by norms that are defined based on volume integrals of pressure and velocity. For the cavity flow, we demonstrate that vector-valued POD modes lead to reduced-order models that are much more effective (accurate and stable) than scalar-valued modes defined independently for different flow variables.", "doi": "10.1109/CDC.2002.1184376", "isbn": "0-7803-7516-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2002-12", "pages": "3273-3278" }, { "id": "authors:9f2jt-mt183", "collection": "authors", "collection_id": "9f2jt-mt183", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:OLFcdc02a", "type": "book_section", "title": "Distributed structural stabilization and tracking for formations of dynamic multi-agents", "book_title": "Proceedings of the 41st IEEE Conference on Decision and Control, December 10-13, 2002, Las Vegas, Nevada, USA", "author": [ { "family_name": "Olfati-Saber", "given_name": "Reza", "clpid": "Olfati-Saber-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We provide a theoretical framework that consists of graph theoretical and Lyapunov-based approaches to stability analysis and distributed control of multi-agent formations. This framework relays on the notion of graph rigidity as a means of identifying the shape variables of a formation. Using this approach, we can formally define formations of multiple vehicles and three types of stabilization/tracking problems for dynamic multi-agent systems. We show how these three problems can be addressed mutually independent of each other for a formation of two agents. Then, we introduce a procedure called dynamic node augmentation that allows construction of a larger formation with more agents that can be rendered structurally stable in a distributed manner from some initial formation that is structurally stable. We provide two examples of formations that can be controlled using this approach, namely, the V-formation and the diamond formation.", "isbn": "0-7803-7516-5", "publisher": "IEEE", "place_of_publication": "Los Alamitos, CA", "publication_date": "2002-12", "pages": "209-215" }, { "id": "authors:fj01n-me678", "collection": "authors", "collection_id": "fj01n-me678", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:OLFcdc02b", "type": "book_section", "title": "Graph rigidity and distributed formation stabilization of multi-vehicle systems", "book_title": "Proceedings of the 41st IEEE Conference on Decision and Control, December 10-13, 2002, Las Vegas, Nevada, USA", "author": [ { "family_name": "Olfati-Saber", "given_name": "Reza", "clpid": "Olfati-Saber-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We provide a graph theoretical framework that allows us to formally define formations of multiple vehicles and the issues arising in uniqueness of graph realizations and its connection to stability of formations. The notion of graph rigidity is crucial in identifying the shape variables of a formation and an appropriate potential function associated with the formation. This allows formulation of meaningful optimization or nonlinear control problems for formation stabilization/tacking, in addition to formal representation of split, rejoin, and reconfiguration maneuvers for multi-vehicle formations. We introduce an algebra that consists of performing some basic operations on graphs which allow creation of larger rigid-by-construction graphs by combining smaller rigid subgraphs. This is particularly useful in performing and representing rejoin/split maneuvers of multiple formations in a distributed fashion.", "isbn": "0-7803-7516-5", "publisher": "IEEE", "place_of_publication": "Los Alamitos, CA", "publication_date": "2002-12", "pages": "2965-2971" }, { "id": "authors:0myqq-78716", "collection": "authors", "collection_id": "0myqq-78716", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160930-145845741", "type": "book_section", "title": "Primitives for Human Motion: A Dynamical Approach", "author": [ { "family_name": "Del Vecchio", "given_name": "Domitilla", "clpid": "Del-Vecchio-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Perona", "given_name": "Pietro", "orcid": "0000-0002-7583-5809", "clpid": "Perona-P" } ], "abstract": "Using tools from dynamical systems theory and systems identification theory we develop the study of primitives for human motion which we refer to as movemes. We\nintroduce basic definitions of dynamical independence\nof linear time-invariant dynamical systems (LTI) and\nsegmentability of signals and we develop classification and segmentation algorithms for two dimensional motions. We test our ideas on data sampled from four human subjects who were engaged in a simple real-life activity including two movemes. Our experiments show that we are able to distinguish between the two movemes and recognize\nthem even when they take place in an activity containing more than one moveme.", "doi": "10.3182/20020721-6-ES-1901.01313", "publisher": "IFAC", "publication_date": "2002-07" }, { "id": "authors:p5ck3-40155", "collection": "authors", "collection_id": "p5ck3-40155", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111109-145851328", "type": "book_section", "title": "Nonlinear control methods for planar carangiform robot fish locomotion", "book_title": "2001 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Morgansen", "given_name": "Kristi A.", "clpid": "Morgansen-K-A" }, { "family_name": "Duindam", "given_name": "Vincent", "clpid": "Duindam-V" }, { "family_name": "Mason", "given_name": "Richard J.", "clpid": "Mason-R-J" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Considers the design of motion control algorithms for robot fish. We present modeling, control design, and experimental trajectory tracking results for an experimental planar robotic fish system that is propelled using carangiform-like locomotion. Our model for the fish's propulsion is based on quasi-steady fluid flow. Using this model, we propose gaits for forward and turning trajectories and analyze system response under such control strategies. Our models and predictions are verified by experiment.", "doi": "10.1109/ROBOT.2001.932588", "isbn": "0-7803-6576-3", "publisher": "IEEE", "place_of_publication": "Pitscataway, NJ", "publication_date": "2001-05", "pages": "427-434" }, { "id": "authors:7tc7z-zr779", "collection": "authors", "collection_id": "7tc7z-zr779", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101008-094957238", "type": "book_section", "title": "J_2 Dynamics and Formation Flight", "book_title": "Proceedings of AIAA Guidance, Navigation, and Control Conference, 2001", "author": [ { "family_name": "Koon", "given_name": "Wang Sang", "clpid": "Koon-W-S" }, { "family_name": "Marsden", "given_name": "Jerrold E.", "clpid": "Marsden-J-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Masdemont", "given_name": "Josep", "clpid": "Masdemont-J" } ], "abstract": "We study the dynamics of the relative motion of\nsatellites in the gravitational field of the Earth, including\nthe effects of the bulge of the Earth (the J_2\neffect). Using Routh reduction and dynamical systems\nideas, a method is found that locates orbits\nsuch that a cluster of satellites remains close with\nvery little dispersing, even with no controls.", "isbn": "9781563474835", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_publication": "Reston, VA", "publication_date": "2001", "pages": "1-7" }, { "id": "authors:7h200-jt424", "collection": "authors", "collection_id": "7h200-jt424", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GLAcdc98", "type": "book_section", "title": "Model reduction, centering, and the Karhunen-Loeve expansion", "book_title": "IEEE Conference on Decision and Control, 37th (CDC 1998), Tampa, FL, 16-18 December 1998", "author": [ { "family_name": "Glava\u0161ki", "given_name": "Sonja", "clpid": "Glava\u0161ki-S" }, { "family_name": "Marsden", "given_name": "Jerrold E.", "clpid": "Marsden-J-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We propose a new computationally efficient modeling method that captures a given translation symmetry in a system. To obtain a low order approximate system of ODEs, prior to performing a Karhunen Loeve expansion, we process the available data set using a \"centering\" procedure. This approach has been shown to be efficient in nonlinear scalar wave equations.", "doi": "10.1109/CDC.1998.758639", "isbn": "0-7803-4394-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1998-12", "pages": "2071-2076" }, { "id": "authors:d9y01-f4g15", "collection": "authors", "collection_id": "d9y01-f4g15", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:KELacc98", "type": "book_section", "title": "Modelling and experimental investigation of carangiform locomotion for control", "book_title": "Proceedings of the 1998 American Control Conference, 21-26 June 1998, Philadelphia PA", "author": [ { "family_name": "Kelly", "given_name": "Scott D.", "clpid": "Kelly-S-D" }, { "family_name": "Mason", "given_name": "Richard J.", "clpid": "Mason-R-J" }, { "family_name": "Anhalt", "given_name": "Carl T.", "clpid": "Anhalt-C-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Burdick", "given_name": "Joel W.", "clpid": "Burdick-J-W" } ], "abstract": "We propose a model for planar carangiform swimming based on conservative equations for the interaction of a rigid body and an incompressible fluid. We account for the generation of thrust due to vortex shedding through controlled coupling terms. We investigate the correct form of this coupling experimentally with a robotic propulsor, comparing its observed behavior to that predicted by unsteady hydrodynamics. Our analysis of thrust generation by an oscillating hydrofoil allows us to characterize and evaluate certain families of gaits. Our final swimming model takes the form of a control-affine nonlinear system.", "doi": "10.1109/ACC.1998.703619", "isbn": "0-7803-4530-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1998-06", "pages": "1271-1276" }, { "id": "authors:qp6q8-rr689", "collection": "authors", "collection_id": "qp6q8-rr689", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142358825", "type": "book_section", "title": "Control of rotating stall in a low-speed axial flow compressor using pulsed air injection: modeling, simulations, and experimental validation", "book_title": "Proceedings of 1995 34th IEEE Conference on Decision and Control", "author": [ { "family_name": "Behnken", "given_name": "Robert L.", "clpid": "Behnken-R-L" }, { "family_name": "D'Andrea", "given_name": "Raffaello", "clpid": "D'Andrea-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Previous results in the use of pulsed air injection for active control of rotating stall have suggested that air injectors have the effect of shifting the steady state compressor characteristic. In this paper we analyze the effect of a compressor characteristic actuation scheme for the three state Moore Greitzer compression system model. It is shown that closed loop feedback based on the square magnitude of the first rotating stall mode can be used to decrease the hysteresis region associated with the transition from unstalled to stalled and back to unstalled operation. The compressor characteristic shifting idea is then applied to a higher fidelity distributed model in which the characteristic shifting has phase content in addition to the magnitude content captured by the three state model. The optimal phasing of the air injection relative to the sensed position of the stall cell is determined via simulation and the results found to agree with those obtained via an experimental parametric study on the Caltech low-speed axial flow compressor.", "doi": "10.1109/cdc.1995.478613", "isbn": "0780326857", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-12", "pages": "3056-3061" }, { "id": "authors:b4yer-qag47", "collection": "authors", "collection_id": "b4yer-qag47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142359062", "type": "book_section", "title": "Robust performance analysis for a class of uncertain nonlinear systems", "book_title": "Proceedings of 1995 34th IEEE Conference on Decision and Control", "author": [ { "family_name": "Tierno", "given_name": "Jorge E.", "clpid": "Tierno-J-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Performance analysis of a large class of nonlinear systems is proven to be equivalent to performance analysis of a constrained uncertain linear system, for which computable analysis methods have already been developed.", "doi": "10.1109/cdc.1995.480382", "isbn": "0780326857", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-12", "pages": "1684-1689" }, { "id": "authors:gpja1-7cy31", "collection": "authors", "collection_id": "gpja1-7cy31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142358906", "type": "book_section", "title": "Configuration controllability for a class of mechanical systems", "book_title": "Proceedings of 1995 34th IEEE Conference on Decision and Control", "author": [ { "family_name": "Lewis", "given_name": "Andrew D.", "clpid": "Lewis-A-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "We define a notion of controllability for mechanical systems which determines the configurations which are accessible from a given configuration. We derive sufficient conditions for this notion of controllability in terms of the given inputs, their Lie brackets, and their covariant derivatives.", "doi": "10.1109/cdc.1995.478914", "isbn": "0780326857", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-12", "pages": "4288-4293" }, { "id": "authors:3pgzc-w6562", "collection": "authors", "collection_id": "3pgzc-w6562", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142358983", "type": "book_section", "title": "Approximate trajectory generation for differentially flat systems with zero dynamics", "book_title": "Proceedings of 1995 34th IEEE Conference on Decision and Control", "author": [ { "family_name": "van Nieuwstadt", "given_name": "Michiel J.", "clpid": "van-Nieuwstadt-M-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes algorithms to generate trajectories for differentially flat systems with zero dynamics. Zero dynamics in flat systems occur when the flat outputs are not the tracking outputs. This means that the output trajectories can be fully parametrized by the flat outputs, but that there is some additional freedom left. This freedom can be exploited to minimize a cost criterion. We parametrize the differentially flat outputs by basis functions, and solve for the parameters so as to track a prescribed trajectory approximately while minimizing a cost function. We give examples of such systems, and present simulations and experimental data. We focus on implementation issues and point out the computational cost involved in the various problems.", "doi": "10.1109/cdc.1995.478902", "isbn": "0780326857", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-12", "pages": "4224-4230" }, { "id": "authors:nqp8v-mae83", "collection": "authors", "collection_id": "nqp8v-mae83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142359220", "type": "book_section", "title": "An experimental comparison of controllers for a vectored thrust, ducted fan engine", "book_title": "Proceedings of 1995 American Control Conference - ACC'95", "author": [ { "family_name": "Kantner", "given_name": "Michael", "clpid": "Kantner-M" }, { "family_name": "Bodenheimer", "given_name": "Bobby", "clpid": "Bodenheimer-B" }, { "family_name": "Bendotti", "given_name": "Pascale", "clpid": "Bendotti-P" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Experimental comparisons between four different control design methodologies are applied to a small vectored thrust engine. Each controller is applied to three trajectories of varying aggressiveness. The control strategies considered are LQR, \u210b\u221e, gain scheduling, and feedback linearization. The experiments show that gain scheduling is essential to achieving good performance. The strengths and weaknesses of each methodology are also examined.", "doi": "10.1109/acc.1995.531229", "isbn": "0780324455", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-06", "pages": "1956-1961" }, { "id": "authors:nzpt9-8h376", "collection": "authors", "collection_id": "nzpt9-8h376", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142359300", "type": "book_section", "title": "An efficient algorithm for performance analysis of nonlinear control systems", "book_title": "Proceedings of 1995 American Control Conference - ACC'95", "author": [ { "family_name": "Tierno", "given_name": "Jorge E.", "clpid": "Tierno-J-E" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Doyle", "given_name": "John C.", "orcid": "0000-0002-1828-2486", "clpid": "Doyle-J-C" } ], "abstract": "A numerical algorithm for computing necessary conditions for performance specifications is developed for nonlinear uncertain systems. The algorithm is similar in nature and behavior to the power algorithm for the \u00b5 lower bound, and does not rely on a descent method. The algorithm is applied to a practical example.", "doi": "10.1109/acc.1995.532342", "isbn": "0780324455", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-06", "pages": "2717-2721" }, { "id": "authors:wsb7y-2d766", "collection": "authors", "collection_id": "wsb7y-2d766", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142359139", "type": "book_section", "title": "The mechanics of undulatory locomotion: the mixed kinematic and dynamic case", "book_title": "Proceedings of 1995 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Ostrowski", "given_name": "Jim", "clpid": "Ostrowski-J-P" }, { "family_name": "Burdick", "given_name": "Joel", "clpid": "Burdick-J-W" }, { "family_name": "Lewis", "given_name": "Andrew D.", "clpid": "Lewis-A-D" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper studies the mechanics of undulatory locomotion. This type of locomotion is generated by a coupling of internal shape changes to external non-holonomic constraints. Employing methods from geometric mechanics, the authors use the dynamic symmetries and kinematic constraints to develop a specialized form of the dynamic equations which govern undulatory systems. These equations are written in terms of physically meaningful and intuitively appealing variables that show the role of internal shape changes in driving locomotion.", "doi": "10.1109/robot.1995.525549", "isbn": "0780319656", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1995-05", "pages": "1945-1951" }, { "id": "authors:mx7y8-13475", "collection": "authors", "collection_id": "mx7y8-13475", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-130817404", "type": "book_section", "title": "Exponential stabilization of driftless nonlinear control systems via time-varying, homogeneous feedback", "author": [ { "family_name": "M'Closkey", "given_name": "Robert T.", "orcid": "0000-0003-1443-8217", "clpid": "M'Closkey-R-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper brings together results from a number of different areas in control theory to provide an algorithm for the synthesis of locally exponentially stabilizing control laws for a large class of driftless nonlinear control systems. The stability is defined with respect to a nonstandard dilation and is termed \"\u03b4-exponential\" stability. The \u03b4-exponential stabilization relies on the use of feedbacks which render the closed loop vector field homogeneous with respect to a dilation. These feedbacks are generated from a modification of Pomet's algorithm (1992) for smooth feedbacks. Converse Lyapunov theorems for time-periodic homogeneous vector fields guarantee that local exponential stability is maintained in the presence of higher order (with respect to the dilation) perturbing terms.", "doi": "10.1109/CDC.1994.411139", "publisher": "IEEE", "publication_date": "1994-12" }, { "id": "authors:4708p-er762", "collection": "authors", "collection_id": "4708p-er762", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190319-091908577", "type": "book_section", "title": "Differential flatness and absolute equivalence", "book_title": "Proceedings of 1994 33rd IEEE Conference on Decision and Control", "author": [ { "family_name": "van Nieuwstadt", "given_name": "M.", "clpid": "van-Nieuwstadt-M-J" }, { "family_name": "Rathinam", "given_name": "M.", "clpid": "Rathinam-M" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper we give a formulation of differential flatness-a concept originally introduced by Fliess, Levine, Martin, and Rouchon (1992)-in terms of absolute equivalence between exterior differential systems. Systems which are differentially flat have several useful properties which can be exploited to generate effective control strategies for nonlinear systems. The original definition of flatness was given in the context of differential algebra, and required that all mappings be meromorphic functions. Our formulation of flatness does not require any algebraic structure and allows one to use tools from exterior differential systems to help characterize differentially flat systems. In particular, we show that in the case of single input control systems (i.e., codimension 2 Pfaffian systems), a system is differentially flat if and only if it is feedback linearizable via static state feedback. However, in higher codimensions feedback linearizability and flatness are not equivalent: one must be careful with the role of time as well the use of prolongations which may not be realizable as dynamic feedbacks in a control setting. Applications of differential flatness to nonlinear control systems and open questions are also discussed.", "doi": "10.1109/CDC.1994.410908", "isbn": "0-7803-1968-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1994-12", "pages": "326-332" }, { "id": "authors:sfw9j-c6p61", "collection": "authors", "collection_id": "sfw9j-c6p61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-093858769", "type": "book_section", "title": "Experiments in exponential stabilization of a mobile robot towing a trailer", "book_title": "Proceedings of 1994 American Control Conference (ACC '94)", "author": [ { "family_name": "M'Closkey", "given_name": "Robert T.", "orcid": "0000-0003-1443-8217", "clpid": "M'Closkey-R-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Applies some previously developed control laws for stabilization of mechanical systems with non-holonomic constraints to an experimental system consisting of a mobile robot towing a trailer. The authors verify the applicability of various control laws which have appeared in the recent literature, and compare the performance of these controllers in an experimental setting. In particular, the authors show that time-periodic, non-smooth controllers can be used to achieve exponential stability of a desired equilibrium configuration, and that these controllers outperform smooth, time-varying control laws. The authors also point out several practical considerations which must be taken into account when implementing these controllers.", "doi": "10.1109/ACC.1994.751893", "isbn": "0-7803-1783-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1994-07", "pages": "988-993" }, { "id": "authors:naf8d-ha130", "collection": "authors", "collection_id": "naf8d-ha130", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-140628400", "type": "book_section", "title": "Design and construction of a small ducted fan engine for nonlinear control experiments", "book_title": "Proceedings of 1994 American Control Conference", "author": [ { "family_name": "Choi", "given_name": "Henry", "clpid": "Choi-Henry" }, { "family_name": "Sturdza", "given_name": "Peter", "clpid": "Sturdza-P" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper describes the design and construction of a small ducted fan engine which is being used for experimental research in robust nonlinear control of high-performance vectored thrust aircraft. The fan consists of a high-efficiency electric motor with a 6-inch diameter blade, capable of generating up to 9 Newtons of thrust. Flaps on the fan allow the thrust to be vectored from side to side and even reversed. The engine is mounted on a three degree of freedom stand which allows horizontal and vertical translation as well as unrestricted pitch angle. We give a detailed description of the design and construction of the fan and its analytical and empirical models. Initial PID controllers for altitude and pitch angle stabilization are included to verify the system model and indicate future avenues of research.", "doi": "10.1109/ACC.1994.735033", "isbn": "0-7803-1783-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1994-07", "pages": "2618-2622" }, { "id": "authors:9tscv-9m103", "collection": "authors", "collection_id": "9tscv-9m103", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-142601604", "type": "book_section", "title": "Nonholonomic mechanics and locomotion: the snakeboard example", "book_title": "Proceedings of the 1994 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Ostrowski", "given_name": "Jim", "clpid": "Ostrowski-J" }, { "family_name": "Lewis", "given_name": "Andrew", "clpid": "Lewis-A-D" }, { "family_name": "Murray", "given_name": "Richard", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Burdick", "given_name": "Joel", "clpid": "Burdick-J-W" } ], "abstract": "Analysis and simulations are performed for a simplified model of a commercially available variant of the skateboard, known as the Snakeboard. Although the model exhibits basic gait patterns seen in a large number of locomotion problems, the analysis tools currently available do not apply to this problem. The difficulty lies primarily in the way in which the nonholonomic constraints enter into the system. As a first step towards understanding systems represented by their model the authors present the equations of motion and perform some controllability analysis for the snakeboard. The authors also perform numerical simulations of possible gait patterns which are characteristic of snakeboard locomotion.", "doi": "10.1109/ROBOT.1994.351153", "isbn": "0-8186-5330-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1994-05", "pages": "2391-2397" }, { "id": "authors:8nycy-k3v09", "collection": "authors", "collection_id": "8nycy-k3v09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-140045299", "type": "book_section", "title": "Trajectory generation for the N-trailer problem using Goursat normal form", "book_title": "32nd IEEE Conference on Decision and Control", "author": [ { "family_name": "Tilbury", "given_name": "D.", "clpid": "Tilbury-D" }, { "family_name": "Murray", "given_name": "R. M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S.", "clpid": "Sastry-S-Shankar" } ], "abstract": "Shows how the machinery of exterior differential systems can be used to help solve nonholonomic motion planning problems. Since the Goursat normal form, for exterior differential systems is dual to chained form for vector fields, the authors solve the problem of steering a mobile robot with N trailers by converting the system into chained form, doing the path-planning in the chained form coordinates, and converting the path back into the original coordinates. Simulations of the N-trailer system parallel parking and backing into a loading dock are included.", "doi": "10.1109/CDC.1993.325330", "isbn": "0-7803-1298-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1993-12", "pages": "971-977" }, { "id": "authors:ngmby-qvv73", "collection": "authors", "collection_id": "ngmby-qvv73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-160152940", "type": "book_section", "title": "Nonholonomic systems and exponential convergence: some analysis tools", "book_title": "Proceedings of 32nd IEEE Conference on Decision and Control", "author": [ { "family_name": "M'Closkey", "given_name": "Robert T.", "orcid": "0000-0003-1443-8217", "clpid": "M'Closkey-R-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "In this paper the authors make a contribution to the analysis of nonholonomic systems with exponential rates of convergence. A key idea is the use of control laws which render the closed loop system homogeneous with respect to a dilation. The analysis is applied to nonholonomic systems in power form and consists of two steps. The first step is a reduction to an invariant set and then the application of an averaging result. The averaging theorem is a stability result for C^0 homogeneous order zero vector fields.", "doi": "10.1109/CDC.1993.325324", "isbn": "0-7803-1298-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1993-12", "pages": "943-948" }, { "id": "authors:4tarb-bky02", "collection": "authors", "collection_id": "4tarb-bky02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-100713740", "type": "book_section", "title": "Applications and extensions of Goursat normal form to control of nonlinear systems", "book_title": "Proceedings of 32nd IEEE Conference on Decision and Control", "author": [ { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "The Goursat normal form theorem gives conditions under which a Pfaffian exterior differential system is equivalent to a certain normal form. This paper details how the Goursat normal form and its extensions provide a unified framework for understanding feedback linearization, chained form, and differential flatness.", "doi": "10.1109/CDC.1993.325849", "isbn": "0-7803-1298-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1993-12", "pages": "3425-3430" }, { "id": "authors:m3bgc-epq27", "collection": "authors", "collection_id": "m3bgc-epq27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-123339977", "type": "book_section", "title": "Convergence Rates for Nonholonomic Systems in Power Form", "book_title": "1993 American Control Conference", "author": [ { "family_name": "M'Closkey", "given_name": "Robert T.", "clpid": "M'Closkey-R-T" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "This paper investigates the convergence rates of several controllers for low dimenional nonholonomic systems in power form. The method of multiple scales is found to be effective in determining the asymptotic form of the solutions. The general form of the perturbation solutions indicates how parameters in the control laws may be chosen to achieve a desired convergence rate. A detailed analysis of controllers exhibiting exponential convergence is included.", "doi": "10.23919/ACC.1993.4793446", "isbn": "0-7803-0860-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1993-06", "pages": "2967-2972" }, { "id": "authors:k6nfw-w6073", "collection": "authors", "collection_id": "k6nfw-w6073", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190320-134725249", "type": "book_section", "title": "Nonholonomic control systems: from steering to stabilization with sinusoids", "book_title": "Proceedings of the 31st IEEE Conference on Decision and Control", "author": [ { "family_name": "Teel", "given_name": "Andrew R.", "clpid": "Teel-A-R" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Walsh", "given_name": "Greg", "clpid": "Walsh-G" } ], "abstract": "The authors present a control law for globally asymptotically stabilizing a class of controllable nonlinear systems without drift. The control law combines earlier work in steering nonholonomic systems using sinusoids at integrally related frequencies, with the ideas in recent results on globally stabilizing linear and nonlinear systems through the use of saturation functions. Simulation results for stabilizing a simple kinematic model of an automobile are included.", "doi": "10.1109/CDC.1992.371456", "isbn": "0-7803-0872-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1992-12", "pages": "1603-1609" }, { "id": "authors:57zdy-p9b76", "collection": "authors", "collection_id": "57zdy-p9b76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190319-101351233", "type": "book_section", "title": "Stabilization of trajectories for systems with nonholonomic constraints", "book_title": "Proceedings 1992 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Walsh", "given_name": "G.", "clpid": "Walsh-G" }, { "family_name": "Tilbury", "given_name": "D.", "clpid": "Tilbury-D" }, { "family_name": "Sastry", "given_name": "S.", "clpid": "Sastry-S-Shankar" }, { "family_name": "Murray", "given_name": "R.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Laumond", "given_name": "J. P.", "clpid": "Laumond-J-P" } ], "abstract": "A technique for stabilizing nonholonomic systems to trajectories is presented. It is well known that such systems cannot be stabilized to a point using smooth static-state feedback. The authors suggest the use of control laws for stabilizing a system about a trajectory, instead of a point. Given a nonlinear system and a desired nominal feasible trajectory, an explicit control law which will locally exponentially stabilize the system to the desired trajectory is given. The theory is applied to several examples, including a car-like robot.", "doi": "10.1109/ROBOT.1992.219987", "isbn": "0-8186-2720-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1992-05", "pages": "1999-2004" }, { "id": "authors:9vh36-1dy86", "collection": "authors", "collection_id": "9vh36-1dy86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-145135101", "type": "book_section", "title": "Steering car-like systems with trailers using sinusoids", "book_title": "Proceedings 1992 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Tilbury", "given_name": "D.", "clpid": "Tilbury-D" }, { "family_name": "Laumond", "given_name": "J.-P.", "clpid": "Laumond-J-P" }, { "family_name": "Murray", "given_name": "R.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" }, { "family_name": "Walsh", "given_name": "G.", "clpid": "Walsh-G" } ], "abstract": "Methods for steering car-like robots with trailers are investigated. A connection is demonstrated between Murray and Sastry's (1990, 1991) work of steering with integrally related sinusoids and Sussmann and Liu's (1991) recent work on asymptotic behavior of systems with high-frequency sinusoids as inputs. The merits of coordinate transformations, relative to the convergence properties, are discussed. Simulation results for a car-like robot with two trailers are presented.", "doi": "10.1109/ROBOT.1992.219988", "isbn": "0-8186-2720-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1992-05", "pages": "1993-1998" }, { "id": "authors:zq8eg-dqa10", "collection": "authors", "collection_id": "zq8eg-dqa10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-132947215", "type": "book_section", "title": "An experimental study of hierarchical control laws for grasping and manipulation using a two-fingered planar hand", "book_title": "1992 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Hollerbach", "given_name": "Karin", "clpid": "Hollerbach-K" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" } ], "abstract": "Compares the performance of hierarchical and single-level controllers in a grasping context, and concludes that for rapid, planar grasping motions of heavy objects the performance of a hierarchical control structure is superior to that of the two single-level controllers tested. Although the theory discussed applies to grasping problems of arbitrary complexity, the focus is on planar, two-fingered grasping for the sake of clarity and to simplify implementation and experimental testing of the proposed control algorithms. The control algorithms have been implemented on a multifingered hand.", "doi": "10.1109/ROBOT.1992.220015", "isbn": "0-8186-2720-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1992-05", "pages": "2770-2775" }, { "id": "authors:mgg1a-7cf80", "collection": "authors", "collection_id": "mgg1a-7cf80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190319-105627176", "type": "book_section", "title": "Steering nonholonomic systems in chained form", "book_title": "Proceedings of the 30th IEEE Conference on Decision and Control", "author": [ { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" } ], "abstract": "The authors introduce a nilpotent form, called a chained form, for nonholonomic control systems. For the case of a nonholonomic system with two inputs, they give constructive conditions for the existence of a feedback transformation which puts the system into chained form, and show how to steer the system between arbitrary states. Examples are presented for steering a car and a car with a trailer attached: other examples can be found in the areas of space robotics and multifingered robot hands. The present results also have applications in the area of nilpotentization of distributions of vector fields on R^n.", "doi": "10.1109/CDC.1991.261508", "isbn": "0-7803-0450-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1991-12", "pages": "1121-1126" }, { "id": "authors:78rcq-fkd03", "collection": "authors", "collection_id": "78rcq-fkd03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190319-081854942", "type": "book_section", "title": "Steering nonholonomic systems using sinusoids", "author": [ { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" } ], "abstract": "Methods for steering systems with nonholonomic constraints between arbitrary configurations are investigated. R.W. Brockett (1981) derived the optimal controls for a set of canonical systems in which the tangent space to the configuration manifold is spanned by the input vector fields and their (first-order) Lie brackets. Using Brockett's result as motivation, the authors derive suboptimal trajectories for systems which are not in canonical form and consider systems in which it takes more than one level of bracketing to achieve controllability. These trajectories use sinusoids at integrally related frequencies to achieve motion at a given bracketing level. Examples and simulation results are presented.", "doi": "10.1109/CDC.1990.203994", "publisher": "IEEE", "publication_date": "1990-12" }, { "id": "authors:6afdr-0h669", "collection": "authors", "collection_id": "6afdr-0h669", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190319-104216033", "type": "book_section", "title": "Nonlinear controllers for non-integrable systems: the Acrobot example", "author": [ { "family_name": "Hauser", "given_name": "John", "clpid": "Hauser-J" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" } ], "abstract": "Recent developments in the theory of geometric nonlinear control provide powerful methods for controller design for a large class of nonlinear systems. Many systems, however, do not satisfy the restrictive conditions necessary for either full state linearization [6, 5] or input-output linearization with internal stability [2]. In this paper, we present an approach to controller design based on finding a linearizable nonlinear system that well approximates the true system over a desirable region.\nWe outline an engineering procedure for constructing\nthe approximating nonlinear system given the true system. We\ndemonstrate this approach by designing a nonlinear controller for a simple mechanical system patterned after a gymnast performing on a single parallel bar.", "doi": "10.23919/ACC.1990.4790817", "publisher": "IEEE", "publication_date": "1990-05" }, { "id": "authors:t5x4c-98828", "collection": "authors", "collection_id": "t5x4c-98828", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-135736981", "type": "book_section", "title": "Control primitives for robot systems", "book_title": "Proceedings 1990 IEEE International Conference on Robotics and Automation", "author": [ { "family_name": "Deno", "given_name": "D. Curtis", "clpid": "Deno-D-C" }, { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Pister", "given_name": "Kristofer S. J.", "clpid": "Pister-K-S-J" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" } ], "abstract": "A methodology is developed for describing of hierarchical control of robot systems in a manner which is faithful to the underlying mechanics, structured enough to be used as an interpreted language, and sufficiently flexible to encompass a wide variety of systems. A consistent set of primitive operations which form the core of a robot system description and control language is presented. This language, motivated by the hierarchical organization of neuromuscular systems, is capable of describing a large class of robot systems under a variety of single-level and distributed control schemes.", "doi": "10.1109/ROBOT.1990.126280", "isbn": "0-8186-9061-5", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1990-05", "pages": "1866-1871" }, { "id": "authors:7arjy-b3y74", "collection": "authors", "collection_id": "7arjy-b3y74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190315-135551524", "type": "book_section", "title": "Control experiments in planar manipulation and grasping", "book_title": "1989 International Conference on Robotics and Automation", "author": [ { "family_name": "Murray", "given_name": "Richard M.", "orcid": "0000-0002-5785-7481", "clpid": "Murray-R-M" }, { "family_name": "Sastry", "given_name": "S. Shankar", "clpid": "Sastry-S-Shankar" } ], "abstract": "Many algorithms have been proposed in the literature for control of multifingered robot hands. The authors compare the performance of several of these algorithms, as well as some extensions of more conventional manipulator control laws, in the case of planar grasping. Based on experiments performed on Styx, the most effective control laws are found to be the simple joint control law and the generalized computed torque law. The computed torque control law is shown to be an attractive alternative for position control of multifingered hands.", "doi": "10.1109/ROBOT.1989.100054", "isbn": "0-8186-1938-4", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "1989-05", "pages": "624-629" } ]