Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning

Autonomous robots in the real world have nonlinear dynamics with actuators that are subject to constraints. The combination of the two poses complicates the task of designing stabilizing controllers that can guarantee safety, which we denote as the stabilize-avoid problem. Existing control-based tec...

Full description

Bibliographic Details
Main Author: So, Oswin
Other Authors: Fan, Chuchu
Format: Thesis
Published: Massachusetts Institute of Technology 2024
Online Access:https://hdl.handle.net/1721.1/155344
_version_ 1826214750934007808
author So, Oswin
author2 Fan, Chuchu
author_facet Fan, Chuchu
So, Oswin
author_sort So, Oswin
collection MIT
description Autonomous robots in the real world have nonlinear dynamics with actuators that are subject to constraints. The combination of the two poses complicates the task of designing stabilizing controllers that can guarantee safety, which we denote as the stabilize-avoid problem. Existing control-based techniques can provide safety and stability guarantees but under the assumption of unbounded control inputs. On the other hand, learning-based techniques can handle control constraints but often are unable to correctly trade-off between safety and stability. In this thesis, we take a step towards synthesizing controllers with improved safety and stability for high dimensional nonlinear systems with control constraints by combining techniques from reachability, optimal control, and reinforcement learning. We first propose a novel approach to solve constrained optimal control problems using deep reinforcement learning by using techniques from traditional constrained optimization, enabling the solution of stabilize-avoid problems for high-dimensional nonlinear systems with control constraints. Next, we present an alternate method of solving the stabilize-avoid problem using control barrier functions, where we present an improved method for learning control barrier functions for nonlinear systems with control constraints by drawing on connections between reachability and deep reinforcement learning. We validate our proposed methods on a variety of benchmark tasks. Our experiments demonstrate the advantage of our methods over existing techniques in terms of improved safety rates and larger regions of attraction, especially in the case of high-dimensional systems.
first_indexed 2024-09-23T16:10:35Z
format Thesis
id mit-1721.1/155344
institution Massachusetts Institute of Technology
last_indexed 2024-09-23T16:10:35Z
publishDate 2024
publisher Massachusetts Institute of Technology
record_format dspace
spelling mit-1721.1/1553442024-06-28T03:04:13Z Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning So, Oswin Fan, Chuchu Massachusetts Institute of Technology. Department of Aeronautics and Astronautics Autonomous robots in the real world have nonlinear dynamics with actuators that are subject to constraints. The combination of the two poses complicates the task of designing stabilizing controllers that can guarantee safety, which we denote as the stabilize-avoid problem. Existing control-based techniques can provide safety and stability guarantees but under the assumption of unbounded control inputs. On the other hand, learning-based techniques can handle control constraints but often are unable to correctly trade-off between safety and stability. In this thesis, we take a step towards synthesizing controllers with improved safety and stability for high dimensional nonlinear systems with control constraints by combining techniques from reachability, optimal control, and reinforcement learning. We first propose a novel approach to solve constrained optimal control problems using deep reinforcement learning by using techniques from traditional constrained optimization, enabling the solution of stabilize-avoid problems for high-dimensional nonlinear systems with control constraints. Next, we present an alternate method of solving the stabilize-avoid problem using control barrier functions, where we present an improved method for learning control barrier functions for nonlinear systems with control constraints by drawing on connections between reachability and deep reinforcement learning. We validate our proposed methods on a variety of benchmark tasks. Our experiments demonstrate the advantage of our methods over existing techniques in terms of improved safety rates and larger regions of attraction, especially in the case of high-dimensional systems. S.M. 2024-06-27T19:46:20Z 2024-06-27T19:46:20Z 2024-05 2024-05-28T19:36:36.012Z Thesis https://hdl.handle.net/1721.1/155344 0000-0002-5411-3663 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle So, Oswin
Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title_full Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title_fullStr Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title_full_unstemmed Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title_short Safe Nonlinear Control Under Control Constraints via Reachability, Optimal Control and Reinforcement Learning
title_sort safe nonlinear control under control constraints via reachability optimal control and reinforcement learning
url https://hdl.handle.net/1721.1/155344
work_keys_str_mv AT sooswin safenonlinearcontrolundercontrolconstraintsviareachabilityoptimalcontrolandreinforcementlearning