Research On The Third Type Balance Problem Of The U-shaped Assembly Line In Stochastic Conditions

The flow-through assembly line is an efficient production method,and assembly is the last integration step in the production process.Nowadays,due to the customization needs of customers and the continuous development of product diversification,enterprises have gradually changed from high-volume and low-variety production modes to flexible production in small batches and varieties.Therefore,assembly and manufacturing enterprises must improve the entire assembly system.Assembly efficiency,flexibility and maneuverability to meet customer needs.With the promotion of lean production methods,enterprises use Ushaped assembly lines more.Compared with traditional linear models,U-shaped assembly lines can save space layout and make assembly production more compact.U-shaped assembly lines can shorten the walking path of operators.Improve the time utilization of workers and reduce physical exertion and waste of resources due to material handling.Therefore,studying the U-shaped assembly line balance theory and finding a fast and efficient solution method is of great significance to the modern enterprise assembly manufacturing system.This paper summarizes and sorts out the background,purpose,significance and research status of assembly line balancing problem at home and abroad;introduces in detail the basic concepts of assembly line,relevant theory of stochastic assembly line balancing,common terms of assembly line balancing,focuses on directed graph theory,its matrix representation and evaluation index of assembly line balancing problem;and minimizes assembly line smoothing system.The mathematical models of the third type of deterministic and stochastic U-shaped assembly line balancing problems are established.Because the model is non-linear,the original model is transformed into an integer linear programming model by linearizing the model.Based on the summary of the solving algorithms of the mathematical models of the assembly line balancing problems,a heuristic search algorithm based on the synthesis rank method is proposed,and the general optimization MATLAB program for solving the above two types of assembly line balancing problems is compiled.Combining with the experimental data of off-road vehicle models,the third problem model of deterministic assembly line balancing is established,and the results of linear and Ushaped assembly line allocation schemes are obtained,and the balancing effect of assembly line balancing schemes is analyzed and compared to verify the superiority of U-shaped assembly line.Finally,the third problem model of stochastic assembly line balancing is established by taking the front bumper assembly experiment of super sports car as an example.The balancing schemes of linear and U-shaped assembly lines are obtained,and the balancing schemes and effects of assembly lines are compared.The effects of different unfinished rates ? on the balancing effect of assembly lines are studied.The model and algorithm of the third kind of balancing problem of stochastic U-shaped assembly lines are validated,which provides a reference for the balancing research of stochastic U-shaped assembly lines.