Decentralized multi-robot exploration under low-bandwidth communications

Abstract

In this paper, we address the problem of coordinating multiple robots to explore large-scale underground areas covered with low-bandwidth communication. Based on the evaluation of existing coordination methods, we found that well-performing methods rely on exchanging significant amounts of data, including maps. Such extensive data exchange becomes infeasible using only low-bandwidth communication, which is suitable for underground environments. Therefore, we propose a coordination method that satisfies low-bandwidth constraints by sharing only the robot’s positions. The proposed method employs a fully decentralized principle called Cross-rank that computes how to distribute robots uniformly at intersections and subsequently orders exploration waypoints based on the traveling salesman problem formulation. The proposed principle has been evaluated based on exploration time, traveled distance, and coverage in five large-scale simulated subterranean environments and a real-world deployment with three quadruped robots. The results suggest that the proposed approach provides a suitable tradeoff between the required communication bandwidth and the time needed for exploration.