Fault-Tolerant Multi-Robot Coordination with Limited Sensing within Confined Environments

TL;DR

This paper introduces a novel fault-tolerance method for multi-robot systems operating in confined spaces with limited sensing, using physical contact interactions to improve robustness and maintain task performance despite robot failures.

Contribution

The study presents the Active Contact Response (ACR) method, a new approach enabling robots to adaptively reposition faulty peers through physical contact, enhancing fault tolerance without global communication.

Findings

ACR significantly reduces recovery time after robot failures.

The method maintains effective collective excavation despite faults.

Experimental results validate improved system robustness in confined environments.

Abstract

As robots are increasingly deployed to collaborate on tasks within shared workspaces and resources, the failure of an individual robot can critically affect the group's performance. This issue is particularly challenging when robots lack global information or direct communication, relying instead on social interaction for coordination and to complete their tasks. In this study, we propose a novel fault-tolerance technique leveraging physical contact interactions in multi-robot systems, specifically under conditions of limited sensing and spatial confinement. We introduce the "Active Contact Response" (ACR) method, where each robot modulates its behavior based on the likelihood of encountering an inoperative (faulty) robot. Active robots are capable of collectively repositioning stationary and faulty peers to reduce obstructions and maintain optimal group functionality. We implement our algorithm in a team of autonomous robots, equipped with contact-sensing and collision-tolerance capabilities, tasked with collectively excavating cohesive model pellets. Experimental results indicate that the ACR method significantly improves the system's recovery time from robot failures, enabling continued collective excavation with minimal performance degradation. Thus, this work demonstrates the potential of leveraging local, social, and physical interactions to enhance fault tolerance and coordination in multi-robot systems operating in constrained and extreme environments.