Collaborative Exploration with Intermittent Communication : Inferring map information from exploration graphs

Sammanfattning: Autonomous robots have a substantial presence in today’s society. A presence which increases with each passing year, as more and more problems may be handled by robots. As challenges in the field of Robotics are conquered, the field expands and new challenges appear. One current frontier is the use of multiple collaborating autonomous robots in environments where wireless communication is hindered. This can for example be cases such as exploration of environments underwater, or in cave-systems. Most research in this context make use of strategies based around sharing exploration goals, without communicating what areas have been explored. While this allows for strategies that can carry out communication with severely limited bandwidth, the collaboration is restricted. This thesis presents a successfully synthesized collaboration strategy, based around the sharing of exploration graphs instead of sharing only exploration goals, while not going so far as to share a detailed map. The strategy makes use of UFOMap and UFOExplorer in order to create a map and exploration graph, and communication is carried out when visual contact is made between robots. This thesis evaluates the use of sharing exploration graphs as a substitute to detailed maps, and as a way of sharing exploration goals when coordinating exploration between robots. In addition to the novelty of the communication framework, a novel way of creating clusters out of exploration goals is studied. Experiments carried out using 3 robots showed promising results for the synthesized strategy, having it perform exploration comparably to a centralized strategy without communication constraints, while still keeping to a low bandwidth. This is when evaluated primarily on the criteria of how thoroughly the environment was explored, how fast it was explored, and how much data was transmitted between robots