Obstacle Avoidance for Unicycle-Modelled Mobile Robots with Time-varying Control Barrier Functions

TL;DR

This paper introduces a real-time safety-critical control method for unicycle-modelled robots using time-varying control barrier functions and control Lyapunov functions, enabling dynamic obstacle avoidance and navigation.

Contribution

It presents a novel control framework that controls both linear and angular velocities for collision avoidance, overcoming previous limitations of control performance.

Findings

Effective collision avoidance demonstrated in simulations

Control framework allows real-time navigation

Integrates CLF and CBFs in a quadratic program

Abstract

In this paper, we propose a safety-critical controller based on time-varying control barrier functions (CBFs) for a robot with an unicycle model in the continuous-time domain to achieve navigation and dynamic collision avoidance. Unlike previous works, our proposed approach can control both linear and angular velocity to avoid collision with obstacles, overcoming the limitation of confined control performance due to the lack of control variable. To ensure that the robot reaches its destination, we also design a control Lyapunov function (CLF). Our safety-critical controller is formulated as a quadratic program (QP) optimization problem that incorporates CLF and CBFs as constraints, enabling real-time application for navigation and dynamic collision avoidance. Numerical simulations are conducted to verify the effectiveness of our proposed approach.