Research On Modeling, Simulation And Optimization Method Of Aircraft Assembly Pulsation Production Line Based On Extended Petri Net

With the rapid development of aviation technology and the increasing in market demand,aircraft manufacturing mode has been changing,how to shorten the manufacturing cycle and achieve rapidly response has become a pressing matter of the moment,the advanced pulse assembly line has become an inevitable trend of the development of aircraft assembly operation mode under the background.Aircraft assembly pulse line can reduce the assembly time greatly by dividing assembly stations,the flexible features makes it adapt to the aircraft production model that small batch production of many varieties well,so it is important to carry out related research.In order to design the aircraft final assembly line well,this paper carries out technical studies for the modeling,simulation and balance optimization of aircraft assembly pulse line,the specific work is as follows:Firstly,the operation mode and content of aircraft assembly pulse line was analyzed,based on the combination of the existing researches on assembly line balancing optimization and the characteristics of aircraft pulse assembly,some targeted performance indexes and reliability evaluation indexes were put forward.Secondly?a modeling method of assembly line based on the extended Petri net(Object-Oriented Timed Petri Nets,OOHTPN)was studied according to the modeling methods of complex discrete system and actual aircraft assembly process,modeling steps and analysis method were discussed as well,then an example with part assembly instructions has been carried out to verify the validity of OOHTPN.Thirdly,according to the actual situation of position dividing and job time definition,a mathematical model was built to solve the minimum number of stations which targeted at the shortest assembly cycle and the highest utilization,then a heuristic algorithm based on the OOHTPN assembly model was studied,the rationality of the model and the correctness of the solution were verified by an example last.Due to the actual assembly line would be affected by many uncertain factors and events,a dynamic scheduling strategy and optimization algorithm based on priority rules were put forward to maintain the normal operation of the pulse line.Finally,the research about the simulation and optimization technology of assembly pulse line based on V6 software platform at the logical level and resource level was carried out,the mapping rules from OOHTPN model to the simulation model of DELMIA V6 was defined and the simulation strategy was made,the results which can verify and improve the research on the division of stations were analyzed.For the convenience of modeling and simulation,secondary development of DELMIA V6 was studied,the simulation model could be established quickly by adding the product level fast division function,the actual assembly process could be related and monitored by adding simulation strategy,the actual assembly operation could be guided by adding the simulation result output function.