| With the rapid development of international market, it is urgent to improve productivity, decrease cost, accelerate update of products, meet the requirement of manufacturing multi-type but few batch of products for every industrial country. In the end of 80's, our country attached importance to import and assimilate advanced technology and equipment abroad. According to the situation of our country, we explored semi-flexible manufacturing system based on absorbing foreign some technology of FMS(Flexible Manufacturing System). AGV(Automated guided vehicle), which is the key basic facility of logistic system, takes change of transporting materials. Every part of flexible manufacturing system is connected into an organic integer because of AGV's transportation. Therefore, AGV is significant to transit traditional pattern into flexible or semi-flexible manufacturing pattern, enhance the ability of marketable competition and gain economic benefit for contemporary corporations.Path Planning is one of the most important parts for realizing vehicle's automation. Its functions in FMS are as follows: increasing system efficiency, saving manufacturing cost, promoting industrial automation, realizing scheduled task under conflict-free condition. Although a single AGV is essential union of FMS, it can't meet the requirement of improving manufacturing efficiency. A logistic system comprised of multiple automated guided vehicles has many advantages that are lacking in the system of a single vehicle. But in MAGVS, some problems that are without the system of a single AGV are confliction, cooperation, communication of mutual automated guided vehicles. So it is necessary to research path planning of multiple AGVS of logistic system.With the practical requirement of MAGVS, the research work of my paper, which obtains project finance, includes the following contents:1. Research on path planning algorithm of a single AGVThe path planning of a single AGV is the base of multiple automated guided vehicles' study. So we discuss how to establish electronic map and introduce the path planning algorithm of a single vehicle.(1) Establishing the electronic map of the netted road.The data structure of the environment e-map should completely demonstrate the road's information. Firstly, we design the data structure based on practical need. Secondly, the technology of Access 2000 is used to develop the database. Furthermore, the method of visiting the database is ADO(ActiveX Data Object). Finally, the electronic map is built through connecting the database and the program.(2) An algorithm of path planning of a single AGVThe distance is selected as optimal goal in the paper, thus the problem of path planning of a single AGV is transformed into the shortest path of a single AGV. In contrast to several methods of obtaining the shortest path, the classical Dijkstra algorithm is used to calculate the shortest path from the starting node to the ending node.The experiment proved that the algorithm is feasible.2. An algorithm of path planning of MAGVSAs far as MAGVS is connected, it is important to plan a conflict-free path for every AGV of the system. Therefore, this paper develops the model of MAGVS' coordinating control in order to describe the process of the discrete control. Then, we settle the confliction of MAGVS using the traffic rules based on priority.(1) Developing the cooperating model of MAGVSCentralized architecture is applied in the paper, it includes two parts: off-line super-control and on-line sub-control. Super-control of the central room belongs to the discrete event system. Contrasted with several methods of developing the model of the discrete system, we adopt CPN(Colored Petri Net) to describe the super-control of MAGVS. By means of pictures and signs, CPN explains the control's process of MAGVS intuitionisticly and compactly and provides good analytic tool for path planning of MAGVS. (2) An algorithm of path planning of MAGVSA central planner and AGV on-line detection are the core...
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