Study Of The Balance Problem Of A Mixed-flow Assembly Line Considering Ergonomics

With the continuous development of Chinese manufacturing industry,mixed-model assembly line,as a high-efficiency,high-flexibility production mode,has been widely used in discrete manufacturing enterprises.In the study of the balance problem of the mixed model assembly line,although the traditional IE method can solve the bottleneck in the production of the assembly line and other problems,it does not take into account the unequal working load of the operator,which not only leads to fatigue,operation error and other phenomena,but also has a significant impact on the stability of the balance of the mixed model assembly line.Therefore,the study of mixed-model assembly line considering ergonomics has important practical guiding significance for assembly production in discrete manufacturing enterprises.This paper takes the mixed-flow assembly line of a home appliance company as the research object.Firstly,the existing problems of the mixed model assembly line are analyzed,and IE method is adopted to improve the mixed model assembly line.Secondly,according to the analysis of the operator's physical consumption in the preliminary improvement results,the balance optimization objective of the mixed model assembly line is determined by combining the actual production demand of the enterprise,and the balance optimization model of the mixed model assembly line in class ? and class section considering the operator's variables is built respectively: One is to obtain the minimum number of work stations under the condition of determining the production beat.The physical and mental load of the operator is taken as the constraint condition of assembly line balance.The other is to consider the fatigue and recovery process of the operator in the production beat when the number of working stations is fixed.The other is to take the fatigue and recovery process of the operator in the production beat into consideration when the number of stations is fixed,in order to obtain the minimum production beat as the goal,and to reasonably distribute the body load of the operator.Third,according to the characteristics of the assembly line balance model,combined with the advantages and disadvantages of various algorithms,the selection of NSGA-? algorithm and algorithm design.Finally,according to the actual data of the enterprise,NSGA-? algorithm is used to solve the two kinds of balance models,and the conclusion is drawn that the class ?optimization scheme has better balance effect for the enterprise.The research results of this paper present an effective strategy to reduce the adverse effects of uneven workload distribution on the assembly line and provide a theoretical support for the further optimization design of the mixed-model assembly line.The study shows that the type ? optimization scheme,which takes ergonomics into consideration,can further improve the balance rate of the assembly line and basically eliminate the difference in the energy consumption of the operators.The research results have a certain practical application value for the improvement of the efficiency of the actual assembly operation and the protection of the operators.