The Research On Modeling Of Assembly Line Based On Timed Transition Petri Net And Cycle Time Optimization

Automated assembly line has become mature production methods in modern factory with the development of science and manufacturing industry.Efficiency and timeliness of product is very important in modern manufacturing industry so that the quality of assembly line design has become a key issue related to the development of enterprise.Therefore,modeling of assembly line and cycle time optimization is of great significance.Domestic and foreign scholars have done a lot of research in the assembly line modeling and cycle time optimization field,this paper describes the research results mainly related to the Petri net model construction of assembly line,Petri net characteristics analysis,assembly line scheduling optimization etc.Firstly,the paper makes a research on the characteristics of assembly process.There are human factors and non-human factors which affects the assembly pace.In order to integrate the effects of non-human factors,the assembly time correction formula is used in the paper.Then author put forward the evaluation system and balance index of assembly line.Considering general features of assembly line author make a model analysis and cycle time optimization on actual assembly line of an enterprise.Secondly,this paper introduces the development process and concept of basic Petri net,and extends it with assembly time correction formula,which formed concept of modified timed transition Petri net(MTTPN),and describes its operation rules and characteristics.S invariant and T invariant is used to analyze the characteristics of MTTPN.Then author proposes the assembly line cycle time data processing algorithm and defines the mobile mean value of cycle time and long mean value which displayed by assembly line cycle time trend graph.Assembly Line Cycle Time Transverse Plato and Process Cycle Time Longitudinal Curves are constructed as the basis for the cycle time optimization analysis.Then design of assembly line management system is introduced in this paper.After analyzing the requirements of assembly line management,author constructs architecture and topology of assembly line management system.And hardware interface and software module are developed on LabVIEW,including data acquisition module,data storage module and cycle time optimization module etc.Finally,the stability and validity of the assembly line management system are verified on semi-automatic assembly line of an enterprise.The management software developed in this project is used to collect and processing the data of the assembly line,and author put forward the assembly line optimization scheme according to cycle time analysis.Then author use the MTTPN to analyze property of the improved assembly line.