DiMPP: a complete distributed algorithm for multi-agent path planning

Abstract

Multi-agent path planning (MAPP) is a challenging task that aims to find conflict free paths for all the agents in a given domain. Priority-based decoupled approach is one of the several approaches to solve a MAPP problem. It works as follows: first, find paths of individual agents and then restructure these paths based on some priority of the agents. Most of the existing decoupled approaches use centralised algorithms. However, multi-agent systems are inherently distributed, where agents have limited information and each agent may not know the total number of agents in the system. Some of these aspects are incorporated in DMAPP. DMAPP is an existing fully distributed algorithm that works in three phases: (i) individual path planning, (ii) priority decision-making and (iii) plan restructuring. However, DMAPP is incomplete, i.e. DMAPP may fail to find a solution, even if it exists. In this paper, we present a new distributed algorithm (DiMPP) which is complete. The computer simulations performed on some well-known benchmark domains reveal that DiMPP outperforms DMAPP in the number of problem instances solved. For larger problem instances, the time taken by DiMPP is orders of magnitude less than that of some existing centralised algorithms.