Research On Key Technology Of Pulse Assembly Line Design For Marine Diesel Engine

With the rapid development of science and technology,the research and development tasks of marine diesel engine are increasing.The traditional fixed assembly mode can not meet the manufacturing requirements of modern marine diesel engine.Therefore,in order to meet the development needs of marine diesel engine manufacturing industry in china,it has gradually become a trend to establish marine diesel engine pulse assembly line by learning from the experience of pulse assembly management mode.Based on the national key scientific research fund project and the research background of school-enterprise cooperation,starting from the actual situation of the marine diesel engine assembly process and the actual demands of related enterprises,this thesis focuses on the key technologies such as workshop stations layout planning and assembly line balancing in the design process of marine diesel engine pulse assembly line.A pulse assembly line design system for marine diesel engine is developed by using a variety of technical means.The main research work is as follows:(1)Based on overall analysis of the implementation process of assembly process information modeling,workshop stations layout planning and assembly line balancing,the overall framework of marine diesel engine pulse assembly line design system is established.By analyzing the characteristics of marine diesel engine pulse assembly process and process data requirements,the related process information model is constructed,and it is used as the only process data source in the system development and design process.(2)In order to meet the demand of workshop stations layout planning in the design process of marine diesel engine pulse assembly line,combined with the actual situation of the enterprise,workshop stations layout planning problem is transformed into a multiline equipment layout optimization problem.Guided by the form of process layout,the total material handling cost and stations area utilization rate are taken as optimization targets with the constraints of the number of stations,the occupied area of stations,the process connection between stations,and the times of material handling between stations,and a multi-objective optimization mathematical model for workshop stations layout problem is established.The initial population,crossover and mutation operations of the traditional genetic algorithm are improved,and the effectiveness of the algorithm is verified through the analysis of an example.At the same time,a better layout plan of workshop stations is solved.(3)Aiming at the demand of assembly line balancing in the design process of marine diesel engine pulse assembly line,combined with the characteristics of marine diesel engine pulse assembly process,the influence of assembly tasks sequence,team number,assembly line beat and other factors on the allocation of assembly tasks in the station are analyzed.With the optimization goal of balancing the distribution of assembly tasks in the station and maximizing the efficiency of the team,a mathematical model of the equilibrium assignment problem of the assembly tasks in the station is established.A hybrid optimization algorithm combining genetic algorithm(GA)and ant colony algorithm(ACO)is designed to solve the problem,and the feasibility of the algorithm is verified by the comparative analysis of examples.Meantime,a better equilibrium assignment scheme of the assembly tasks in the station is solved.(4)Based on the above research content,combined with the actual needs of enterprises,a pulse assembly line design system for marine diesel engine is developed,which realizes order information management,process information management,workshop stations layout planning,assembly line balancing and other functions.According to the analysis of an example,the practicability of the system is proved.