运输网络的最短有向路Petri网仿真算法

随着对综合交通体系和智能交通研究的逐步深入,发现必须解决运输需求和运输网络分析的技术问题。在已有的方法中,只有对有向网络有比较成熟的理论和方法,然而,运输网络却是无向的。本文内容是论述如何借助于Petri网论和Petri网图计算机仿真将无向交通运输网络转换为Petri网表示的有向图,并同时求出相应的运输网络中OD（起点终点）对的最短有向路径及路长。本文以图的形式给出Petri网的定义,通过导入“时间Place”和“标记”的附加描述,使Petri网成为扩充的Petri网（EPN）。定义Petri网图仿真器的运行规则和步骤,用Petri网图仿真器、自动将无向运输网络转换成EPN模型,然后自动求出相应的最短有向路径和路长。通过显示、打印或电信号,为用户提供信真报告或电信号。

Petri Net Simulation Arithmetic of the Shortest Directional Path in Transportation Net

With the development of the research in comprehensive traffic system and intelligent traffic system, the technical problem to transportation requirement analysis and network analysis is supposed to be resolved firstly. On the other hand, all the existing mature theory and methods are only for directional network, but not suitable for non directional transportation network. This paper presents how to convert the non directional transportation net into Petri net denoted directional graph with the help of Petri net theory and Petri net simulator, meanwhile finding the corresponding shortest path of the transportation network. In this paper, Petri net is defined by net graph, and by introducing the "time place" and "token", Petri net becomes enlarged Perti net (EPN). According to the running rules and steps, Petri net simulator can convert the nondirectional transportation net into EPN model and then work out its shortest path automatically. Finally, simulational results return to the user in form of screen displaying or printed reports.