Publication

G. Sharon, R. Stern, A. Felner and N. Sturtevant. Conflict-Based Search for Optimal Multi-Agent Path Finding. In Proceedings of the AAAI Conference on Artificial Intelligence (AAAI), 2012.

Abstract: In the multi-agent path finding problem (MAPF) paths should be found for several agents, each with a different start and goal position such that agents do not collide. Previous optimal solvers applied global A*-based searches. We present a new search algorithm called Conflict Based Search (CBS). CBS is a two-level algorithm. At the high level, a search is performed on a tree based on conflicts between agents. At the low level, a search is performed only for a single agent at a time. In many cases this reformulation enables CBS to examine fewer states than A* while still maintaining optimality. We analyze CBS and show its benefits and drawbacks. Experimental results on various problems shows a speedup of up to a full order of magnitude over previous approaches.

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