A Collaboration Mechanism on Positive Interactions in Multi-agent Environments

In multi-agent environments where agents independently generate and execute plans to satisfy their goals, the resulting plans may sometimes overlap. In this paper, we propose a collaboration mechanism using social law, through which rational agents can smoothly delegate and receive the execution of the overlapping parts of plans in order to reduce the cost of plan execution. Also, we consider col laboration with agents that do not abide by social law, that is, self-centered agents. Simulation results show that our mechanism also has the property of balancing t he cost of plan execution and shows flexibility towards self-centered agents. 1 Introduction In multi-agent environments where agents generate and execute plans which satisfy their own goals, plans are generated independently, thus two relationships [Mar-tial, 1992] exist among plans. The first is called a negative relationship and exists between plans which attempt to use the same resource at the same time. This relationship will cause conflicts. Such conflicts must be avoided or resolved because they prevent actions from being properly executed. The other relation is called a positive relationship and exists between plans which include overlapping subplans, subplans consisting of both common actions and individual actions. When there is a positive relationship and one agent delegates the execution of the overlapping subplan to the other agent, it can reduce the cost of execution. A lot of research has been done on negative relationships , such as conflict avoidance, by using a social law [Shoham and Tennenholtz, 1992] and conflict resolution based on game theory [Zlotkin and Rosenschein, 1990]. However, despite the importance of a positive relationship for the agents' effective execution of plans, not much has been made [Foulser et al., 1991] to utilize this, except to reduce costs by deleting the overlapping actions in a domain consisting of only one agent [Hayes, 1989] and for multi-agent systems where irrational agents delegate and receive plans [Martial, 1992] and for multi-agent systems where agents mutually construct a collaborative plan [Osawa and Tokoro, 199l]. In this paper we propose a collaboration mechanism by which rational agents can delegate and receive sub-plans in a positive relationship so that the cost of ex ecution is reduced. If an agent delegates its actions to the other agent, it can reduce the execution cost greatly and benefit from it. On the other hand, when an agent receives actions, the cost increases a little even though the reduction in …