no code implementations • 4 Apr 2025 • Jason J. Choi, Christopher A. Strong, Koushil Sreenath, Namhoon Cho, Claire J. Tomlin
The reachable set computed based on the DDH is also ensured to be a conservative approximation of the true reachable set.
no code implementations • 15 Oct 2024 • Sampada Deglurkar, Haotian Shen, Anish Muthali, Marco Pavone, Dragos Margineantu, Peter Karkus, Boris Ivanovic, Claire J. Tomlin
We present a novel perspective on the design, use, and role of uncertainty measures for learned modules in an autonomous system.
1 code implementation • 7 Feb 2024 • Will Lavanakul, Jason J. Choi, Koushil Sreenath, Claire J. Tomlin
As such, we believe that the new notion of the discriminating hyperplane offers a more generalizable direction towards designing safety filters, encompassing and extending existing certificate-function-based or safe RL methodologies.
no code implementations • 26 Oct 2023 • Jason J. Choi, Donggun Lee, Boyang Li, Jonathan P. How, Koushil Sreenath, Sylvia L. Herbert, Claire J. Tomlin
This strong link we establish between the reachability problem and the barrier constraint, while guaranteeing the continuity of the value function, is not achievable by previous backward reachability-based formulations.
no code implementations • 13 Sep 2023 • Alonso Marco, Elias Morley, Claire J. Tomlin
In this paper, we propose (i) a novel approach to embed existing domain knowledge in the kernel and (ii) an OoD online runtime monitor, based on receding-horizon predictions.
no code implementations • 4 Jul 2023 • Matthias Killer, Marius Wiggert, Hanna Krasowski, Manan Doshi, Pierre F. J. Lermusiaux, Claire J. Tomlin
We propose a dynamic programming-based method to efficiently solve for the optimal growth value function when true currents are known.
no code implementations • 4 Jul 2023 • Andreas Doering, Marius Wiggert, Hanna Krasowski, Manan Doshi, Pierre F. J. Lermusiaux, Claire J. Tomlin
We demonstrate the safety of our approach in such realistic situations empirically with large-scale simulations of a vessel navigating in high-risk regions in the Northeast Pacific.
no code implementations • 4 Jul 2023 • Nicolas Hoischen, Marius Wiggert, Claire J. Tomlin
Next, we design a low-interference safe interaction (LISIC) policy that trades off the performance policy and the safety control to ensure safe and performant operation.
1 code implementation • 10 Oct 2022 • Michael H. Lim, Tyler J. Becker, Mykel J. Kochenderfer, Claire J. Tomlin, Zachary N. Sunberg
Thus, when combined with sparse sampling MDP algorithms, this approach can yield algorithms for POMDPs that have no direct theoretical dependence on the size of the state and observation spaces.
no code implementations • 23 Aug 2022 • Fernando Castañeda, Jason J. Choi, Wonsuhk Jung, Bike Zhang, Claire J. Tomlin, Koushil Sreenath
We then present the pointwise feasibility conditions of the resulting safety controller, highlighting the level of richness that the available system information must meet to ensure safety.
no code implementations • 5 Apr 2022 • Tyler Westenbroek, Anand Siththaranjan, Mohsin Sarwari, Claire J. Tomlin, Shankar S. Sastry
However, despite the extensive impacts of methods such as receding horizon control, dynamic programming and reinforcement learning, the design of cost functions for a particular system often remains a heuristic-driven process of trial and error.
1 code implementation • 23 Mar 2022 • Shankar A. Deka, Alonso M. Valle, Claire J. Tomlin
Koopman spectral theory has grown in the past decade as a powerful tool for dynamical systems analysis and control.
no code implementations • 18 Mar 2022 • Jingqi Li, Donggun Lee, Somayeh Sojoudi, Claire J. Tomlin
We address this problem by designing a new value function with a contracting Bellman backup, where the super-zero level set, i. e., the set of states where the value function is evaluated to be non-negative, recovers the reach-avoid set.
1 code implementation • 23 Dec 2021 • Kai-Chieh Hsu, Vicenç Rubies-Royo, Claire J. Tomlin, Jaime F. Fisac
Recent successes in reinforcement learning methods to approximately solve optimal control problems with performance objectives make their application to certification problems attractive; however, the Lagrange-type objective used in reinforcement learning is not suitable to encode temporal logic requirements.
1 code implementation • 17 Dec 2021 • Sampada Deglurkar, Michael H. Lim, Johnathan Tucker, Zachary N. Sunberg, Aleksandra Faust, Claire J. Tomlin
The Partially Observable Markov Decision Process (POMDP) is a powerful framework for capturing decision-making problems that involve state and transition uncertainty.
no code implementations • 21 Sep 2021 • Shankar A. Deka, Donggun Lee, Claire J. Tomlin
Collaboration between interconnected cyber-physical systems is becoming increasingly pervasive.
no code implementations • 25 Jun 2021 • Donggun Lee, Claire J. Tomlin
Based on the Lax formula [2], this paper proposes an HJ formula for the state-constrained optimal control problem for nonlinear systems.
no code implementations • 13 Jun 2021 • Fernando Castañeda, Jason J. Choi, Bike Zhang, Claire J. Tomlin, Koushil Sreenath
However, since these constraints rely on a model of the system, when this model is inaccurate the guarantees of safety and stability can be easily lost.
no code implementations • 6 Apr 2021 • Jason J. Choi, Donggun Lee, Koushil Sreenath, Claire J. Tomlin, Sylvia L. Herbert
This paper works towards unifying two popular approaches in the safety control community: Hamilton-Jacobi (HJ) reachability and Control Barrier Functions (CBFs).
no code implementations • 9 Mar 2021 • Andrea Bajcsy, Anand Siththaranjan, Claire J. Tomlin, Anca D. Dragan
This enables us to leverage tools from reachability analysis and optimal control to compute the set of hypotheses the robot could learn in finite time, as well as the worst and best-case time it takes to learn them.
1 code implementation • 28 Jan 2021 • Margaret P. Chapman, Riccardo Bonalli, Kevin M. Smith, Insoon Yang, Marco Pavone, Claire J. Tomlin
In addition, we propose a second definition for risk-sensitive safe sets and provide a tractable method for their estimation without using a parameter-dependent upper bound.
no code implementations • 15 Jan 2021 • Sylvia Herbert, Jason J. Choi, Suvansh Sanjeev, Marsalis Gibson, Koushil Sreenath, Claire J. Tomlin
However, work to learn and update safety analysis is limited to small systems of about two dimensions due to the computational complexity of the analysis.
1 code implementation • 18 Dec 2020 • Michael H. Lim, Claire J. Tomlin, Zachary N. Sunberg
This paper introduces Voronoi Progressive Widening (VPW), a generalization of Voronoi optimistic optimization (VOO) and action progressive widening to partially observable Markov decision processes (POMDPs).
no code implementations • 14 Nov 2020 • Fernando Castañeda, Jason J. Choi, Bike Zhang, Claire J. Tomlin, Koushil Sreenath
This paper presents a method to design a min-norm Control Lyapunov Function (CLF)-based stabilizing controller for a control-affine system with uncertain dynamics using Gaussian Process (GP) regression.
no code implementations • 1 Nov 2020 • David Fridovich-Keil, Claire J. Tomlin
In this paper, we present a method for finding approximate Nash equilibria in a broad class of reachability games.
no code implementations • 7 Sep 2020 • Shankar A. Deka, Dušan M. Stipanović, Claire J. Tomlin
Convolutional and recurrent neural networks have been widely employed to achieve state-of-the-art performance on classification tasks.
no code implementations • 16 Apr 2020 • Jason Choi, Fernando Castañeda, Claire J. Tomlin, Koushil Sreenath
In this paper, the issue of model uncertainty in safety-critical control is addressed with a data-driven approach.
no code implementations • L4DC 2020 • Fernando Castañeda, Mathias Wulfman, Ayush Agrawal, Tyler Westenbroek, Claire J. Tomlin, S. Shankar Sastry, Koushil Sreenath
The main drawbacks of input-output linearizing controllers are the need for precise dynamics models and not being able to account for input constraints.
no code implementations • 6 Apr 2020 • Tyler Westenbroek, Eric Mazumdar, David Fridovich-Keil, Valmik Prabhu, Claire J. Tomlin, S. Shankar Sastry
This paper proposes a framework for adaptively learning a feedback linearization-based tracking controller for an unknown system using discrete-time model-free policy-gradient parameter update rules.
no code implementations • 29 Oct 2019 • Somil Bansal, Andrea Bajcsy, Ellis Ratner, Anca D. Dragan, Claire J. Tomlin
We construct a new continuous-time dynamical system, where the inputs are the observations of human behavior, and the dynamics include how the belief over the model parameters change.
no code implementations • 29 Oct 2019 • Tyler Westenbroek, David Fridovich-Keil, Eric Mazumdar, Shreyas Arora, Valmik Prabhu, S. Shankar Sastry, Claire J. Tomlin
We present a novel approach to control design for nonlinear systems which leverages model-free policy optimization techniques to learn a linearizing controller for a physical plant with unknown dynamics.
1 code implementation • 10 Oct 2019 • Michael H. Lim, Claire J. Tomlin, Zachary N. Sunberg
Partially observable Markov decision processes (POMDPs) with continuous state and observation spaces have powerful flexibility for representing real-world decision and control problems but are notoriously difficult to solve.
1 code implementation • 1 Oct 2019 • David Fridovich-Keil, Vicenc Rubies-Royo, Claire J. Tomlin
Iterative linear-quadratic (ILQ) methods are widely used in the nonlinear optimal control community.
Systems and Control Computer Science and Game Theory Multiagent Systems Robotics Systems and Control
no code implementations • 25 Sep 2019 • Jun Liu, Beitong Zhou, Weigao Sun, Ruijuan Chen, Claire J. Tomlin, Ye Yuan
In this paper, we propose a novel technique for improving the stochastic gradient descent (SGD) method to train deep networks, which we term \emph{PowerSGD}.
no code implementations • 12 Sep 2019 • Thomas Beckers, Somil Bansal, Claire J. Tomlin, Sandra Hirche
In this work, we present a framework to optimize the kernel and hyperparameters of a kernel-based model directly with respect to the closed-loop performance of the model.
1 code implementation • 10 Sep 2019 • David Fridovich-Keil, Ellis Ratner, Anca D. Dragan, Claire J. Tomlin
We benchmark our method in a three-player general-sum simulated example, in which it takes < 0. 75 s to identify a solution and < 50 ms to solve warm-started subproblems in a receding horizon.
Systems and Control Robotics Systems and Control
no code implementations • 1 May 2019 • Andrea Bajcsy, Somil Bansal, Eli Bronstein, Varun Tolani, Claire J. Tomlin
Our safety method is planner-agnostic and provides guarantees for a variety of mapping sensors.
Robotics
no code implementations • 19 Nov 2018 • David Fridovich-Keil, Jaime F. Fisac, Claire J. Tomlin
We present a new framework for motion planning that wraps around existing kinodynamic planners and guarantees recursive feasibility when operating in a priori unknown, static environments.
Robotics Systems and Control
no code implementations • 31 May 2018 • Jaime F. Fisac, Andrea Bajcsy, Sylvia L. Herbert, David Fridovich-Keil, Steven Wang, Claire J. Tomlin, Anca D. Dragan
In order to safely operate around humans, robots can employ predictive models of human motion.
no code implementations • 14 Feb 2018 • Somil Bansal, Shromona Ghosh, Alberto Sangiovanni-Vincentelli, Sanjit A. Seshia, Claire J. Tomlin
We propose a context-specific validation framework to quantify the quality of a learned model based on a distance measure between the closed-loop actual system and the learned model.
no code implementations • 16 Nov 2017 • Datong P. Zhou, Claire J. Tomlin
Secondly, for the adversarial case in which the entire sequence of rewards and costs is fixed in advance, we derive an upper bound on the regret of order $O(\sqrt{NB\log(N/K)})$ utilizing an extension of the well-known $\texttt{Exp3}$ algorithm.
2 code implementations • 12 Oct 2017 • David Fridovich-Keil, Sylvia L. Herbert, Jaime F. Fisac, Sampada Deglurkar, Claire J. Tomlin
Motion planning is an extremely well-studied problem in the robotics community, yet existing work largely falls into one of two categories: computationally efficient but with few if any safety guarantees, or able to give stronger guarantees but at high computational cost.
Systems and Control Computer Science and Game Theory
1 code implementation • 21 Sep 2017 • Somil Bansal, Mo Chen, Sylvia Herbert, Claire J. Tomlin
Hamilton-Jacobi (HJ) reachability analysis is an important formal verification method for guaranteeing performance and safety properties of dynamical systems; it has been applied to many small-scale systems in the past decade.
Systems and Control Dynamical Systems Optimization and Control
no code implementations • 27 Mar 2017 • Somil Bansal, Roberto Calandra, Ted Xiao, Sergey Levine, Claire J. Tomlin
Real-world robots are becoming increasingly complex and commonly act in poorly understood environments where it is extremely challenging to model or learn their true dynamics.
no code implementations • 21 Mar 2017 • Sylvia L. Herbert, Mo Chen, SooJean Han, Somil Bansal, Jaime F. Fisac, Claire J. Tomlin
We propose a new algorithm FaSTrack: Fast and Safe Tracking for High Dimensional systems.
Robotics
no code implementations • 10 Nov 2016 • Frank Jiang, Glen Chou, Mo Chen, Claire J. Tomlin
To sidestep the curse of dimensionality when computing solutions to Hamilton-Jacobi-Bellman partial differential equations (HJB PDE), we propose an algorithm that leverages a neural network to approximate the value function.
no code implementations • 24 Mar 2016 • Ye Yuan, Mu Li, Jun Liu, Claire J. Tomlin
We propose a new method to accelerate the convergence of optimization algorithms.