任务分解的Petri网方法及有效性研究

任务的分解是实现多主体系统的关键,运用形式化的方法对任务分解进行描述和验证是十分必要的。对于一般的任务逻辑分解表达式,利用Petri网对任务的分解进行建模,得到任务分解Petri网,进而通过剔除不合理的任务分解结构得到任务有效分解的Petri网系统。通过检查任务有效分解的Petri网的存在与否,可以判断任务的分解结构是否有效。另外,对于任意一个有限的P/T网系统,给出了判断是否存在无效任务分解的充分条件,从而论证了在任务有效分解的Petri网系统中只存在一级活变迁。将任务分解的有效性判断与Petri网活性分析联系起来,实现了多主体系统的一个亟待解决的基础性问题。

The Petri Net Method of Task Decomposition and Its Validity Research

Task decomposition is the key to multi-agent system implementation.It is necessary to describe and validate the task decomposition structure by a formal method.The task decomposition is modeled by Petri Nets for the ordinary logical expressions of task decomposition,and the Petri net of task decomposition is obtained,after deleting unreasonable structure of task decomposition,the Petri net of valid task decomposition is obtained.By checking whether the Petri net of valid task decomposition exists,the task decomposition is valid or not can be judged.Furthermore,for any finite P/T net,the sufficient conditions for judging if invalid task decomposition structure exists,are proposed,and accordingly that only first-level live transitions exist in the valid task decomposition Petri net system is proven.The fundamental problem is solved by combination of task decomposition validation and liveness of Petri net system.