Research On Modeling And Scheduling Optimization Of Central Tool Magazine System Based On Petri Net

With the continuous improvement of the efficiency and the complexity of parts processed on the production line,the rapid response of tools has become one of the necessary conditions for the efficient manufacturing of equipment,especially for the precision large-scale equipment of the production line.The tool change process is complicated and the manual tool change can no longer meet the flexible and efficient manufacturing needs.Therefore,it is a great practical significance and application value to centrally configure the central tool magazine for large-scale precision equipment on the production line to achieve rapid and accurate configuration of processing tools.This article combine with the national science and the technology major project "Large Metal Shell Section Rapid Development Demonstration Production Line"(2016ZX04002004),which conduct a systematic and in-depth study around the design,modeling and simulation verification of the central tool magazine system.First,the demand and technological requirements of the large-scale CNC boring machine for the central tool magazine system are studied.Based on the Huazhong system platform and robotic hand,the overall scheme of the CNC boring machine central tool magazine system is designed.The color Petri net and the time Petri net modeling method of the central tool magazine system is proposed,which realize the digital modeling of the central tool magazine of the production line.Secondly,the relationship between tool scheduling and shop scheduling are studied.The difference between the traditional workpiece flow and the tool flow are analyzed.And the minimum operating time of the system is taken as the optimization goal,the tool flow synthesis based on workpiece flow is established scheduling model.According to the scheduling optimization characteristics of the central tool magazine system,a scheduling optimization strategy combining the genetic algorithm and the simulated annealing algorithm is realized.The algorithm implementation process is designed in detail and the influence of tool resources is considered.A three-layer chromosome coding structure is proposed,and the software for scheduling optimization of the central tool magazine system is designed.Finally,according to the actual production task requirements,a simulation experiment based on actual working conditions is carried out.Experimental results prove that the fusion algorithm has better performance than the traditional genetic algorithm.Under the limited tool resources,scheduling algorithm can reduce the waiting time and improve the utilization rate of machine tools.The coloring time Petri net is used for modeling and analysis.The reachability tree and S invariant analysis are used to verify the effectiveness and practicability of the model under this scheduling.