Q-learning-based Model-free Safety Filter

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sue, Guo Ning, Choudhary, Yogita, Desatnik, Richard, Majidi, Carmel, Dolan, John, Shi, Guanya
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913591444111360
author Sue, Guo Ning
Choudhary, Yogita
Desatnik, Richard
Majidi, Carmel
Dolan, John
Shi, Guanya
author_facet Sue, Guo Ning
Choudhary, Yogita
Desatnik, Richard
Majidi, Carmel
Dolan, John
Shi, Guanya
contents Ensuring safety via safety filters in real-world robotics presents significant challenges, particularly when the system dynamics is complex or unavailable. To handle this issue, learning-based safety filters recently gained popularity, which can be classified as model-based and model-free methods. Existing model-based approaches requires various assumptions on system model (e.g., control-affine), which limits their application in complex systems, and existing model-free approaches need substantial modifications to standard RL algorithms and lack versatility. This paper proposes a simple, plugin-and-play, and effective model-free safety filter learning framework. We introduce a novel reward formulation and use Q-learning to learn Q-value functions to safeguard arbitrary task specific nominal policies via filtering out their potentially unsafe actions. The threshold used in the filtering process is supported by our theoretical analysis. Due to its model-free nature and simplicity, our framework can be seamlessly integrated with various RL algorithms. We validate the proposed approach through simulations on double integrator and Dubin's car systems and demonstrate its effectiveness in real-world experiments with a soft robotic limb.
format Preprint
id arxiv_https___arxiv_org_abs_2411_19809
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Q-learning-based Model-free Safety Filter
Sue, Guo Ning
Choudhary, Yogita
Desatnik, Richard
Majidi, Carmel
Dolan, John
Shi, Guanya
Robotics
Artificial Intelligence
Systems and Control
Ensuring safety via safety filters in real-world robotics presents significant challenges, particularly when the system dynamics is complex or unavailable. To handle this issue, learning-based safety filters recently gained popularity, which can be classified as model-based and model-free methods. Existing model-based approaches requires various assumptions on system model (e.g., control-affine), which limits their application in complex systems, and existing model-free approaches need substantial modifications to standard RL algorithms and lack versatility. This paper proposes a simple, plugin-and-play, and effective model-free safety filter learning framework. We introduce a novel reward formulation and use Q-learning to learn Q-value functions to safeguard arbitrary task specific nominal policies via filtering out their potentially unsafe actions. The threshold used in the filtering process is supported by our theoretical analysis. Due to its model-free nature and simplicity, our framework can be seamlessly integrated with various RL algorithms. We validate the proposed approach through simulations on double integrator and Dubin's car systems and demonstrate its effectiveness in real-world experiments with a soft robotic limb.
title Q-learning-based Model-free Safety Filter
topic Robotics
Artificial Intelligence
Systems and Control
url https://arxiv.org/abs/2411.19809