The development of flexible part routing controller based on Petri nets and AND/OR graph

• Main Authors: Ja-ling Lin, 林佳伶
• Other Authors: Yu-cheng Kao
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/10510063744149101967

碩士 === 朝陽科技大學 === 工業工程與管理系碩士班 === 89 === This research proposes a new approach to design a flexible real-time dispatching controller for an automated flexible manufacturing systems. In this approach, the flexible part routing problem is solved by representing part routings with AND/OR graphs and modeling production resource controls with Colored Petri Nets (CPN) separately. For each step of a part, the AND/OR routing graph is employed to determine the next machine in which the part will be processed. The machine selection process is guided by the A* heuristic search method under the consideration of both current machine status and selected scheduling rules. CPN resource graphs are used to simulate part traveling among machines necessary to visit, send machine selection request and receive machine selection results for each part, and pass dispatching commands to real parts and production devices. Integration of these two modules makes the dispatching decisions and control much easier to implement from the viewpoint of modeling and software development. A flexible real-time dispatching software has been developed and two examples have been used to illustrate the proposed approach. The results show that the proposed approach can effectively cope with the real time dispatching problem for multiple parts with multiple routings.