Affiliations: Graduate School of ISEE, Kyushu University, Fukuoka, 819-0395 Japan, E-mail: {tasaki@agent., yabu@agent., iwanari@agent., yokoo@}is.kyusyu-u.ac.jp | IBM T.J. Watson Research Center, 1101 Kirchawan Road, Route 134, Yorktown Heights, NY 10598, USA, E-mail: [email protected] | Singapore Management University, 178902 Singapore, Singapore, E-mail: [email protected] | University of Southern California, Los Angeles, CA 90089, USA, E-mail: [email protected]
Abstract: The Networked Distributed POMDPs (ND-POMDPs) can model multiagent systems in uncertain domains and have begun to scale-up the number of agents. However, prior work in ND-POMDPs has failed to address communication. Without communication, the size of a local policy at each agent within the ND-POMDPs grows exponentially in the time horizon. To overcome this problem, we extend existing algorithms so that agents periodically communicate their observation and action histories with each other. After communication, agents can start from new synchronized belief state. Thus, we can avoid the exponential growth in the size of local policies at agents. Furthermore, we introduce an idea that is similar to the Point-based Value Iteration algorithm to approximate the value function with a fixed number of representative points. Our experimental results show that we can obtain much longer policies than existing algorithms as long as the interval between communications is small.
Keywords: Multi-agent system, distributed POMDPs, communication
