Generating multi-agent plans by distributed intersection of Finite State Machines

Abstract

Deterministic multi-agent planning described by MA-STRIPS formalism requires mixture of coordination and synthesis of local agents' plans. All agents' plans, as sequences of actions, can be implicitly described by an appropriate generative structure. Having all local plans of all participating agents described by such a structure and having a merged process of such structures, we can induce a global multi-agent plan by successive elimination of unfeasible combinations of local agents' plans. We use Nondeterministic Finite State Machines (NFSs) as the generative structure for plans and a well-known process of intersection of NFSs to prune the plan spaces towards globally feasible multi-agent plan. Since the numbers of the plans can be large, we use iterative process of building of the NFSs using a state-of-the-art classical planner interleaved with the NFS intersecting process. We have evaluated the algorithm on an extensive number of problems from International Planning Competition extended for multi-agent planning.