领域知识的获取是智能规划研究中的重要内容之一.派生规则是一种基于逻辑推理的领域知识表示方法.在对动作模型和派生规则综合分析的基础上提出了基于派生谓词的STRIPS领域知识提取策略,并给出了该提取策略的算法描述.在规划求解过程中,利用提取所得的领域规则可减少派生规则的逻辑推导,从而提高规划效率.对任意一个规划领域,利用提取所得的领域规则可以分析出领域谓词之间的互斥关系,这种互斥关系可以对一类矛盾的规划状态进行判定.最后,把所提出的领域规则提取策略嵌入到规划器StepByStep之中进行了领域规则提取实验.实验结果验证了该提取算法的可行性和有效性,所提取出的领域规则能够直观地表达谓词问的因果关系,为派生谓词的真值判断和后续的规划求解提供了可靠的领域知识.
Domain knowledge acquisition is essential in the AI planning. Derived rule is a representation to the domain knowledge based on logical reasoning. On the basis of the action model and derived rules analysis, this paper proposes a strategy of extracting domain know/edge for STRIPS world based on derived predicates and the algorithm GetDomainRule for the strategy. The domain rules extracted by the algorithm are used to reduce the logical deduction of derived rules, enhancing the efficiency of the planning. For any domain, the mutex properties of any domain can be obtained between predicates from the domain rules, applied in judging the inconsistent planning state. Finally, the strategy proposed in this paper is embedded in the planner StepByStep and experiments are conducted to extract domain rules. Experimental results show the feasibility and validity of the algorithm GetDomainRule, and the domain rules extracted by the algorithm express the causal relations between predicates directly, providing reliable domain knowledge for determining the true values of derived predicates and the following planning.