Rearrangement Task by Multiple Robots Using a Territorial Approach

In this paper, we address a rearrangement task involving multiple robots. We focus on small working environments composed of narrow corridors. In such an environment, interference between robots resulting from a competition for physical space can affect the overall performance in a rearrangement task. Because of the enormous amount of calculation time required to develop a motion plan for each robot considering the effect of interference, it is difficult to apply the former approach directly. In this paper, we propose a practical method using a territorial approach where the working area of each robot is defined so that there is no overlap. Because robots can develop a motion plan with less consideration of interference between other robots, the entire calculation time can be reduced. In this method, we obtain the order of sub-task executions as a solution to a project scheduling problem. However, some constraints that have not been dealt with in research involving scheduling may arise. We analyzed these new constraints and proposed a metaheuristic strategy to determine the order of sub-tasks. The proposed method is tested in a simulated environment with up to four mobile robots, 12 movable objects, and a complicated arrangement of objects.