Research On Operator-Machine Interference Mechanism For U-shaped Assembly Line

The manufacturing industry is the mainstay of the national economy,and is the foundation of the nation,the instrument of the nation's prosperity,and the foundation of the nation's strength.With the continuous promotion of lean thinking,the U-shaped assembly line has become the most important production configuration for lean manufacturing enterprises.In a U-shaped assembly line,there is both cooperation and interference between operator and machine.In a operator-machine workstation,as the operator-machine ratio increases,the system cost expense gradually decreases,but the man-machine interference phenomenon gradually becomes serious,and the production efficiency decreases.Therefore,it is of theoretical and practical significance to study the reasonable task allocation and propose a reasonable production management.This paper focuses on the general framework of operator-machine ratio analysis,and takes a operator-machine workstation in a U-shaped assembly line as the research object,aiming to reveal the relationship between interference time,cost and production performance under the operator-machine interference mechanism.Using the Markov process,NSGAII algorithm and Plant Simulation software to explore the operator-machine configuration and its corresponding cost issues.The main research of this paper is as follows.(1)For the operator-machine interference phenomenon in the U-shaped assembly line,the operator-machine interference time is defined,a set of operator-machine interference time equations is innovatively established,and the solution process is given.In addition,the operator-machine interference edge(ideal)state equation is proposed through deductive reasoning,and the general analysis framework affecting the operator-machine ratio is constructed from three perspectives of human,machine and other factors,and the internal logical cause-effect diagram between each influencing factor is given.(2)In order to seek the relationship between cost and interference,the optimal touring unit construction scheme is obtained with the help of NSGAII algorithm for the demand situation where orders arrive randomly and the minimum employment cost of the assembly line and the maximum service level of the system are the objectives.Through numerical experiments,the effects of different factors on the hiring cost of the assembly line and the service level of the system are given.(3)To investigate the effects of different production task assignments on the production performance of the U-shaped assembly line,modeling simulations are performed in the Plant Simulation environment to compare the effects of different task assignments on operator and machine.Using the synthetic method,the U-shaped assembly line is structurally modeled by considering operator-machine interference as a "machine failure".The accuracy of the structured modeling of the U-shaped assembly line is verified by two functions,and the production recommendations based on this modeling are used to support the production manager's decision making,which is useful for reducing production costs and improving production efficiency.