Multiple robot rearrangement problem using an extended project-scheduling problem solver

In this paper, we address a multiple robot rearrangement problem. We focus on a small working environment composed of narrow corridors. In such an environment, adequate priority settings are required to prevent robots from having collisions. As a result, enormous calculation time is required. We propose a practical method utilizing partitions that divide the entire complicated problem into multiple simple sub-problems. Among these sub-problems, new constraints related to task execution order occur. Therefore, we extend the existing project-scheduling problem solver to cope with these new constraints. The proposed method is tested in a simulated environment with up to 4 mobile robots and 12 movable objects. The simulation results show that our method can be used to obtain a solution in a feasible calculation time.