Distributed Communicative Exploration under underwater communication constraints

Exploration by Unmanned Underwater Vehicles (UUV) is of interest in different application areas of Safety, Security, and Rescue Robotics (SSRR) including infrastructure inspection after disasters, military reconnaissance, marine search and rescue, and mine hunting. A multi-robot system performing exploration can be highly beneficial for this purpose by distributing the work amongst the different robots. In this paper, we present a distributed approach to multi-robot exploration which always keeps all the robots in communication range. The algorithm is based on a utility function that guarantees communication while using best effort for the exploration itself. The robots randomly sample configuration changes of the overall system, i.e., the set of the next best joined movements based on this utility function. This process can be very well distributed with very few communication overhead by having each robot computing a part of the sample and broadcasting its best candidate configuration change found. The globally best candidate among the broadcasted ones is then executed by the team. The algorithm is tested in a high-fidelity marine robotics simulator including realistic vehicle physics and proper underlying software for mapping, path-planning, and motion-control.