基于Petri网的机床座类柔性生产线调度模型

Scheduling model of machine tool seat flexible production line based on Petri net

在柔性生产线的调度过程中,存在柔性单元间关系复杂且离散并行的问题,为此,以机床座类柔性生产线为例,提出了一种适用于柔性生产线调度研究的Petri网模型。首先,分析了Petri网的组成结构,设计了柔性单元变迁的延时函数;然后,分析了生产线中各柔性单元的生产调度关系,建立了柔性单元的模块化Petri网模型;最后,采用了模块化柔性单元简化座类柔性生产线的Petri网调度模型,研究了生产调度过程中多个系统与柔性单元间信息的传递关系,建立了基于信息流的Petri网模型;通过采用可达树分析法,研究了可能出现的变迁序列,设计了Petri网的可达树图,对所建立的Petri网模型的可行性进行了验证。研究结果表明:基于Petri网建立的机床座类柔性生产调度模型是可行的、合理的,可进一步在此基础上进行柔性生产线的动态生产调度。

Aiming at the problem of complex and discrete parallel relationships among flexible units in the scheduling process of flexible production lines,a Petri net model applicable to the scheduling study of flexible production lines was proposed,taking the flexible production lines of machine tool holders as an example.Firstly,the composition structure of Petri net was analyzed,and the delay function of flexible unit variation was designed.Then,the production scheduling relationship of each flexible unit in the production line was analyzed,and the modular Petri net model of flexible unit was established.Finally,the scheduling Petri net model of modular flexible unit simplified seat class flexible production line was adopted,and the transfer relationship between multiple systems and flexible units in the production scheduling process was studied,and the Petri net model based on information flow was established.The information transfer relationship between multiple systems and flexible units in the production scheduling process was studied,and the Petri net model based on information flow was established.The reachable tree analysis method was adopted to study all possible change sequences,and the reachable tree diagram of Petri net was designed to verify the feasibility of the established Petri net model.The research results show that the flexible production scheduling model of machine tool seat class based on Petri net was feasible and reasonable,and the dynamic production scheduling of flexible production line can be further carried out on this basis.