DisCoF: Cooperative Pathfinding in Distributed Systems with Limited Sensing and Communication Range

Cooperative pathfinding is often addressed in one of two ways in the literature. In fully coupled approaches, robots are considered together and the plans for all robots are constructed simultaneously. In decoupled approaches, the plans are constructed only for a subset of robots at a time. While decoupled approaches can be much faster than fully coupled approaches, they are often suboptimal and incomplete. Although there exist a few decoupled approaches that achieve completeness, global information (which makes global coordination possible) is assumed. Global information may not be accessible in distributed robotic systems. In this paper, we provide a window-based approach to cooperative pathfinding with limited sensing and communication range in distributed systems (called DisCoF). In DisCoF, robots are assumed to be fully decoupled initially, and may gradually increase the level of coupling in an online and distributed fashion. In some cases, e.g., when global information is needed to solve the problem instance, DisCoF would eventually couple all robots together. DisCoF represents an inherently online approach since robots may only be aware of a subset of robots in the environment at any given point of time. Hence, they do not have enough information to determine non-conflicting plans with all the other robots. Completeness analysis of DisCoF is provided.