基于Petri网的多剪多冲加工工艺建模及算法研究

Modeling and algorithm research on machining process of multi-shear and multi-punch base on Petri nets

针对目前硅钢片数控横剪线存在的问题,以实现多剪多冲、系统柔性化,以及降低人员编程量和劳动强度等为目的,对多剪多冲数控横剪线进行研究。分析横剪线的机械结构与工艺流程,给出多剪多冲的定义;以时间Petri网为理论基础建立TPN模型,分析其内部存在的并发、冲突等关系;建立以加工工步最少、送料轴移动总距离最少,以及退料最少为优化目标的数学模型,利用横剪线的并行性,安排多工步加工的有序n元组;给出系统总体算法流程,重点对计算和优化部分进行算法设计;最后通过实例验证多剪多冲数控横剪线加工模型的可行性和有效性。

Aiming at the problems existing in the CNC transverse shear line of silicon steel sheet, a multi-shear and multi-punch CNC transverse shear line research is carried out for the purpose of realizing multi-shear and multi-punching, flexible system, reducing programming quantity and labor intensity. The mechanical structure and process flow of transverse shear line are analyzed, and the definition of multi-shear and multi-punch is given. The TPN model is established based on the time Petri net,and the relationship of concurrency and conflict is analyzed. The mathematical model with least process step, minimum total moving distance of feed axis and minimum return material is set up, the ordered n-tuple of the multi-step machining is arranged by the parallelism of the transverse shear line. The overall algorithm flow is given ,with emphasis on the design and calculation of the algorithm. Finally, an example is given to demonstrate the feasibility and effectiveness of the multi-shear and multi-punch CNC transverse shear line machining model.