Decentralized Connectivity Maintenance with Time Delays using Control Barrier Functions

TL;DR

This paper presents a control strategy based on Control Barrier Functions for maintaining connectivity in multi-robot systems, addressing real-world issues like communication delays through a heuristic validated in simulations and physical experiments.

Contribution

The paper introduces a practical implementation of a connectivity maintenance controller using Control Barrier Functions that accounts for communication delays in real-world multi-robot systems.

Findings

Communication delays significantly affect system performance.

A heuristic effectively mitigates delays in both simulation and real robots.

The approach enhances robustness of connectivity maintenance in practical scenarios.

Abstract

Connectivity maintenance is crucial for the real world deployment of multi-robot systems, as it ultimately allows the robots to communicate, coordinate and perform tasks in a collaborative way. A connectivity maintenance controller must keep the multi-robot system connected independently from the system's mission and in the presence of undesired real world effects such as communication delays, model errors, and computational time delays, among others. In this paper we present the implementation, on a real robotic setup, of a connectivity maintenance control strategy based on Control Barrier Functions. During experimentation, we found that the presence of communication delays has a significant impact on the performance of the controlled system, with respect to the ideal case. We propose a heuristic to counteract the effects of communication delays, and we verify its efficacy both in simulation and with physical robot experiments.