Decentralized Method for Sub-Swarm Deployment and Rejoining

Abstract

As part of swarm search and service (SSS) missions, robots are tasked with servicing jobs as they are sensed. This requires small sub-swarm teams to leave the swarm for a specified amount of time to service the jobs. In doing so, fewer robots are required to change motion than if the whole swarm were diverted, thereby minimizing the job's overall effect on the swarm's main goal. We explore the problem of removing the required number of robots from the swarm, while maintaining overall swarm connectivity. By preserving connectivity, robots are able to successfully rejoin the swarm upon completion of their assigned job. These robots are then made available for reallocation. We propose a decentralized and asynchronous method for breaking off sub-swarm groups and rejoining them with the main swarm using the swarm's communication graph topology. Both single and multiple job site cases are explored. The results are compared against a full swarm movement method. Simulation results show that the proposed method outperforms a full swarm method in the average number of messages sent per robot in each step, as well as, the distance traveled by the swarm.