A Learning-Based Control Barrier Function for Car-Like Robots: Toward Less Conservative Collision Avoidance

Fuente: arXiv
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Main Authors: Xu, Jianye, Alrifaee, Bassam
Format: Preprint
Published: 2024
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author Xu, Jianye
Alrifaee, Bassam
author_facet Xu, Jianye
Alrifaee, Bassam
contents We propose a learning-based Control Barrier Function (CBF) to reduce conservatism in collision avoidance for car-like robots. Traditional CBFs often use the Euclidean distance between robots' centers as a safety margin, which neglects their headings and approximates their geometries as circles. Although this simplification meets the smoothness and differentiability requirements of CBFs, it may result in overly conservative behavior in dense environments. We address this by designing a safety margin that considers both the robot's heading and actual shape, thereby enabling a more precise estimation of safe regions. Because this safety margin is non-differentiable, we approximate it with a neural network to ensure differentiability. In addition, we propose a notion of relative dynamics that makes the learning process tractable. In a case study, we establish the theoretical foundation for applying this notion to a nonlinear kinematic bicycle model. Numerical experiments in overtaking and bypassing scenarios show that our approach reduces conservatism (e.g., requiring 33.5% less lateral space for bypassing) without incurring significant extra computation time. Code: https://github.com/bassamlab/sigmarl
format Preprint
id arxiv_https___arxiv_org_abs_2411_08999
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Learning-Based Control Barrier Function for Car-Like Robots: Toward Less Conservative Collision Avoidance
Xu, Jianye
Alrifaee, Bassam
Robotics
Multiagent Systems
Systems and Control
We propose a learning-based Control Barrier Function (CBF) to reduce conservatism in collision avoidance for car-like robots. Traditional CBFs often use the Euclidean distance between robots' centers as a safety margin, which neglects their headings and approximates their geometries as circles. Although this simplification meets the smoothness and differentiability requirements of CBFs, it may result in overly conservative behavior in dense environments. We address this by designing a safety margin that considers both the robot's heading and actual shape, thereby enabling a more precise estimation of safe regions. Because this safety margin is non-differentiable, we approximate it with a neural network to ensure differentiability. In addition, we propose a notion of relative dynamics that makes the learning process tractable. In a case study, we establish the theoretical foundation for applying this notion to a nonlinear kinematic bicycle model. Numerical experiments in overtaking and bypassing scenarios show that our approach reduces conservatism (e.g., requiring 33.5% less lateral space for bypassing) without incurring significant extra computation time. Code: https://github.com/bassamlab/sigmarl
title A Learning-Based Control Barrier Function for Car-Like Robots: Toward Less Conservative Collision Avoidance
topic Robotics
Multiagent Systems
Systems and Control
url https://arxiv.org/abs/2411.08999