Reconfiguration Method Of Mobile Phone Assembly Line Based On Line Balancing And Buffer Allocation Coupled Optimization

In recent years,with the acceleration of the replacement of mobile phone products,mobile phone manufacturers are facing a series of problems,such as tight order delivery,falling profit margins and increased market competition.Mobile phone assembly companies urgently need assembly lines that can respond quickly to those customers who have different order quantities and product types.In this context,the reconfigurable mobile phone assembly line came into being.Its main feature is the integration of the concept of reconfigurable manufacturing system into the reconfigurable assembly line,modularizing the entire assembly line,production automation and global flexibility.The assembly line system not only can cope with market changes of multiple varieties and variable batches,but also has the ability to produce and reconfigure quickly.As a new type of manufacturing system,the reconfigurable mobile phone assembly line has drawn broad attention and been researched by many enterprises and scholars recently,but the reconstruction optimization methods and technologies for this type of assembly line are still in the early ages of development.Based on the predecessors,this paper further studies the reconstruction optimization method of reconfigurable assembly line,aiming at minimizing the change of assembly line configuration and maximizing the delivery capacity,focusing on solving the reconstruction optimization problem of coordinating the assembly lines' balance and buffer configuration,and finally achieving the successful reconstruction of the assembly line.According to the polymorphism of the reconfigurable assembly line,a method for solving the equivalent model of the assembly line with finite buffer and converting to the assembly line without buffer is proposed,and the Universal Generating Function(UGF)is used.Polynomial calculation advantages give a calculation method with the expected production capacity of a finite buffer assembly line.In this paper,the unit and system hierarchical modeling is adopted for overcoming the difficulty of obtaining the state space of the assembly line and the complex calculation of the steady state capacity of the system.At the unit level,the equivalent model with finite buffer is studied,and the states of the buffer in the assembly process is divided into full,empty,incoming,and empty.At the system level,the generalized generation function(UGF)polynomial calculation advantage is utilized,and the failure state space and probability space of the entire assembly line are obtained by the series-parallel operator.For the reconstruction problem of reconfigurable mobile phone assembly line,the quantitative calculation method of buffer capacity change degree and assembly resource change degree is given,and the line with minimum change of assembly line configuration and maximum capacity is constructed.An optimized mathematical model of balance and buffer configuration is proposed.A reconstruction optimization algorithm based on Pareto multiobjective genetic algorithm based on assembly line balancing and buffer allocation is proposed,including assembly line initial configuration determination strategy and workstation segmentation based bottleneck identification method.In the multi-objective genetic operation,a chromosome coding and decoding mechanism based on workstation partitioning and buffer allocation and a cross-variation method that satisfies the job priority relationship are proposed.The group ranking,elite retention strategy,Pareto solution filter and niche technologies are comprehensively applied,and the algorithm is verified by the basic data of the enterprise,which shows the effectiveness of the algorithm.A mobile phone assembly line management system and simulation integration platform were built,and the reconstruction scheme was verified by near physical 3D simulation.In order to verify and avoid the problems in assembly line reconstruction process,the position and action scene of the assembly equipment resource object in the real assembly line can be fully displayed in the digital simulation world through the construction of the mobile phone assembly line reconstruction management system and the simulation integration test platform.The research work of the paper can effectively solve the problem of reconstruction of the mobile phone assembly line,reduce the production cost of the enterprise to a certain extent,improve the competitiveness of the products in terms of price,and promote the automation and intelligence of the mobile phone assembly line.