Robust Control Barrier Functions using Uncertainty Estimation with Application to Mobile Robots

Fuente: arXiv
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Main Authors: Das, Ersin, Burdick, Joel W.
Format: Preprint
Published: 2024
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author Das, Ersin
Burdick, Joel W.
author_facet Das, Ersin
Burdick, Joel W.
contents This paper proposes a safety-critical control design approach for nonlinear control affine systems in the presence of matched and unmatched uncertainties. Our constructive framework couples control barrier function (CBF) theory with a new uncertainty estimator to ensure robust safety. We use the estimated uncertainty, along with a derived upper bound on the estimation error, for synthesizing CBFs and safety-critical controllers via a quadratic program-based feedback control law that rigorously ensures robust safety while improving disturbance rejection performance. We extend the method to higher-order CBFs (HOCBFs) to achieve safety under unmatched uncertainty, which may cause relative degree differences with respect to control input and disturbances. We assume the relative degree difference is at most one, resulting in a second-order cone constraint. We demonstrate the proposed robust HOCBF method through a simulation of an uncertain elastic actuator control problem and experimentally validate the efficacy of our robust CBF framework on a tracked robot with slope-induced matched and unmatched perturbations.
format Preprint
id arxiv_https___arxiv_org_abs_2401_01881
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Robust Control Barrier Functions using Uncertainty Estimation with Application to Mobile Robots
Das, Ersin
Burdick, Joel W.
Systems and Control
Robotics
This paper proposes a safety-critical control design approach for nonlinear control affine systems in the presence of matched and unmatched uncertainties. Our constructive framework couples control barrier function (CBF) theory with a new uncertainty estimator to ensure robust safety. We use the estimated uncertainty, along with a derived upper bound on the estimation error, for synthesizing CBFs and safety-critical controllers via a quadratic program-based feedback control law that rigorously ensures robust safety while improving disturbance rejection performance. We extend the method to higher-order CBFs (HOCBFs) to achieve safety under unmatched uncertainty, which may cause relative degree differences with respect to control input and disturbances. We assume the relative degree difference is at most one, resulting in a second-order cone constraint. We demonstrate the proposed robust HOCBF method through a simulation of an uncertain elastic actuator control problem and experimentally validate the efficacy of our robust CBF framework on a tracked robot with slope-induced matched and unmatched perturbations.
title Robust Control Barrier Functions using Uncertainty Estimation with Application to Mobile Robots
topic Systems and Control
Robotics
url https://arxiv.org/abs/2401.01881