Consensus-Based Control Barrier Function for Swarm

Abstract

In swarm control, many robots coordinate their actions in a distributed and decentralized way. We propose a consensus-based control barrier function (CCBF) for a swarm. CCBF restricts the states of the whole distributed system, not just those of the individual robots. The barrier function is approximated by a consensus filter. We prove that CCBF constrains the control inputs for holding the forward invariance of the safety set. Moreover, we applied CCBF to a practical problem and conducted an experiment with actual robots. The results showed that CCBF restricted the states of multiple robots to the safety set. To the best of our knowledge, this is the first CBF that can restrict the state of the whole distributed system with only local communication. CCBF has various applications such as monitoring with a swarm and maintaining the network between a swarm and a base station.