面向集成电路制造的基于Petri网的生产调度

本文提出了一个新的面向集成电路(IC)制造的调度方法,核心内容包括两方面:首先,用本文提出的扩展定时Petri 网对IC生产工艺进行描述;其次,对所得Petri 网模型的状态空间进行搜索,得到以Transition序列表示的最优或近似最优调度.该方法可以很好地描述IC制造系统中存在的多制造路径、资源共享、可变晶片组及并发等特性,通过引入测试弧增强Petri 网的建模能力,进而在调度模型上对设备维护、设备优先级以及操作优先级进行描述,而且支持多目标的评价函数,使得到的调度结果更具实用价值.文中给出试验结果表明了算法的有效性.

Petri Net Based Scheduling for Integrated Circuits Manufacturing

Petri net modeling combined with heuristic search provides a new scheduling method for Integrated Circuits (IC) manufacturing systems.The method includes two steps.First,it formulates the scheduling problem with extended timed-place Petri net model.Second,with the help of heuristic function to limit the search space,it applies a search algorithm to reachability graph of the Petri net model to find an optimal or near optimal feasible schedule in terms of the firing sequence of the transitions.Introducing the test arc to traditional timed-place Petri net,this paper proposed a new Petri net,the extended timed-place Petri net.It can concisely represent not only features of IC manufacturing system,such as routing flexibility,shared resources,varied lot sizes,etc.,but also the device maintenance,device priority and operation priority.Therefore,the schedule obtained is more practical.Experimental results are presented to show the effectiveness of the method.