Exploiting Subgraph Structure in Multi-Robot Path Planning

Multi-robot path planning is difficult due to the combinatorial explosion of the search space with every new robot added. Complete search of the combined state-space soon intractable. In this paper we present a novel form of abstraction that allows an much more efficiently. The key to this abstraction is the partitioning of the map into subgraphs of known structure with entry and exit restrictions which we can represent compactly. Planning then becomes a search in the much smaller space of subgraph ations. Once an abstract plan is found, it can be quickly resolved into a correct (but possibly sub-optimal) concrete plan without the need for further search. We prove that this technique is sound and complete and demonstrate its practical effectiveness on a real map. A contending solution, prioritised planning, is also evaluated and shown to have similar performance albeit at the cost of completeness. The two approaches are not necessarily conflicting; we demonstrate how they can be combi...

• Type: Journal
• Year: 2008
• Where: JAIR
• Authors: Malcolm Ross Kinsella Ryan
• Keywords: Combinatorial Explosion, JAIR 2008, Multi-robot Path, Planning