Abstract: Multi-agent system MAS is a very active research direction in the field of artificial intelligence.In multi-agent systems,action conflicts will inevitably occur due to the difference in beliefs between agents.The rigorous coordination method proposed by Sakama et al.is only applicable to situations where there is a common belief among agents.When there is no common belief,this coordination method has no solution.In order to solve this problem,this paper proposed a belief coordination method based on possiblistic answer set programming (PASP).Firstly,according to different belief sets of agents,the weighted quantitative method is used to calculate the satisfaction degree of PASP’s answer set relative to Agent’s belief,so as to weaken some beliefs,and the default decision theory is introduced to deduce the consis-tent solution of Agent’s belief coordination.Then,a consistent coordination program is constructed according to the consistent solution,which serves as the background knowledge base commonly recognized by agents.Finally,the multi-agent belief coordination algorithm is implemented to enable the belief coordination among agents to be completed auto-nomously based on the DLV solver.The example of tourism recommendation system shows that this algorithm can break the limitations of rigorous coordination method and effectively solve the coordination problem when there is no common belief among all agents.

Key words: Coordination program, Default decision theory, Multi-agent system, Possibilistic answer set programming, Weighted quantitative