Safety Barrier Certificates for Heterogeneous Multi-Robot Systems

TL;DR

This paper introduces a formal control framework using barrier certificates to ensure collision avoidance in heterogeneous multi-robot systems, applicable in both centralized and distributed settings, with verified simulations and experiments.

Contribution

It develops a novel safety barrier certificate approach for heterogeneous robots, extending to distributed control with local identification, ensuring minimally invasive collision avoidance.

Findings

Guarantees collision-free behavior in heterogeneous multi-robot systems.

Validated effectiveness through simulation and real-world experiments.

Extends safety barrier certificates to distributed multi-agent control.

Abstract

This paper presents a formal framework for collision avoidance in multi-robot systems, wherein an existing controller is modified in a minimally invasive fashion to ensure safety. We build this framework through the use of control barrier functions (CBFs) which guarantee forward invariance of a safe set; these yield safety barrier certificates in the context of heterogeneous robot dynamics subject to acceleration bounds. Moreover, safety barrier certificates are extended to a distributed control framework, wherein neighboring agent dynamics are unknown, through local parameter identification. The end result is an optimization-based controller that formally guarantees collision free behavior in heterogeneous multi-agent systems by minimally modifying the desired controller via safety barrier constraints. This formal result is verified in simulation on a multi-robot system consisting of both cumbersome and agile robots, is demonstrated experimentally on a system with a Magellan Pro robot and three Khepera III robots.