Research On The Balance And Personnel Scheduling Of The Double-station Assembly Line Of Frame

With the continuous improvement of China’s comprehensive national strength,China’s high-speed bullet train group has entered the stage of rapid development,and China has successfully joined the ranks of the world’s high-speed railway powers.With the "eight vertical and eight horizontal" planning and the construction of "One Belt and One Road",the demand for high-speed railway in China is accelerating.As one of the core components of high-speed bullet train,the efficiency of production and maintenance of bogie plays a decisive role in the efficiency of production and maintenance of high-speed bullet train.Frame assembly is an important link in bogie production and maintenance,because of its characteristics of complex assembly process,high manual assembly requirements and low degree of automation,the traditional method of assembly line design and optimization based on manual experience is no longer applicable to the design and optimization of frame assembly line.The combination of evolutionary algorithm and discrete event modeling and simulation technology provide an important approach and theoretical basis for solving the above problem.In this paper,the balance model and worker scheduling model of double-station mixed-flow assembly line are established.Combined with actual project,the assembly line of an architecture group is optimized from two aspects: assembly line balance and worker resource scheduling,and analyzed the results by simulation.The main contents of this paper are as follows:(1)This paper studied the the balance problem of double-station mixed-flow assembly line,analyzed its the optimization objectives and difficulties.According to the the characteristics and difficulties of large product volume,no cache and the quantity and duration of different products are different of the double-station mixed-flow assembly line balance problem,the balance model of double-station mixed-flow assembly line are established.(2)According to the characteristics of the double-station mixed-flow assembly line,this paper designed the initialization population,objective function solution,selection operator,crossover operator and mutation operator of the genetic algorithm: using multiple encodings to produce the initial population,and using iterative method to solve the plan of process distribution.This paper used the balance model of double-station mixed-flow assembly line to balance the frame groups hang assembly lines,the equilibrium rate and smoothness index of the frame group hanging assembly line after balancing are improved obviously.(3)Considering the difference between the type of work and the level of proficiency of workers,this paper analysised the change of actual process time of double-station mixed-flow assembly line when workers are distributed.On this basis,static scheduling model of workers of the double-station mixed-flow assembly line which considered the difference of worker skill was established to maintain the production takt after balancing the assembly line.On the basis of assembly line balance,this paper solved the production sequence and scheduling plan of the frame groups hang assembly lines.Aimed at the scene of workers need to leave temporarily because of special circumstances,a dynamic scheduling model was established when workers are on temporary leave.The dynamic scheduling scheme was solved according to the workers leave data generated randomly,and the dynamic scheduling scheme was compared with static scheduling scheme through the gantt chart.(4)This paper researched the steps of discrete event modeling simulation,established the simulation model of frame groups hang assembly lines and used secondary development to expand the three dimensional and set logical relationship of the simulation model.The actual process distribution scheme,assembly line balance scheme and worker static scheduling scheme are simulated respectively,and compared and analyzed three sets of simulation results to verify the effectiveness of the balance model and the static scheduling model of workers of the double-station mixed-flow assembly line.It is proved that the schemes can effectively improve the balance performance and productivity of the assembly line.This paper established the balance model and the scheduling model of workers of the double-station mixed-flow assembly line commonly used for hanging assembly lines on frame groups,and solved the actual frame group hanging assembly line using genetic algorithm.The rationality and effectiveness of the scheme was verified by discrete event modeling and simulation technique.The models in this paper have certain guiding significance to balance optimization and worker scheduling of frame group hanging assembly line.