Study On Modeling And Optimization Of Batching Area Logistics Process For Multi-Product Assembly Workshop

In order to meet different needs of customers, multi-product assembly is arelatively common mode of production. In order to improve the efficiency of batchingarea in mixed assembly plant, accelerate the batching area labors’ sorting speed, andreduce the material handling time during the process of supplementing the batchingarea, a multi-product assembly workshop in real application from an enterprise is theresearch object. Through analyzing the bottleneck of the batching area logisticsprocess in the existing mixed assembly plant, material supplementing optimizationproblem and material storage assignment layout optimization problem of the batchingarea are refined. The complex logistics process of batching area in the assemblyworkshop is modeled and optimized. The research content mainly has followingseveral points:(1) The composition of multi-product assembly workshop and the basic attributesof the batching area are studied. The control logic model of the batching area andmaterial handling system, the simulation model of automatic guided vehicle (AGV)system in batching area are built. Simulation models of the batching area, materialhandling system and assembly line are integrated together.(2) The material handling problems of the batching area in supplementingprocess are studied. A mathematical model with the AGV task allocation as decisionvariables is built. The constraints are AGV routes and AGV quantity. The model is tominimize the time used for material handling in supplementing process. I n order toavoid illegal solutions, the combination method of integer code and multi-parametercode, initial population creation method of expansion on chromosome in discrete random population, and a sectional type of crossover method and mutating methodare proposed. Improved genetic algorithm is formed. Multiple tasks allocationproblem and scheduling problem for multiple AGVs are solved and optimized.(3) The material storage assignment problem in batching area is studied. Theconcept of labor’s average routing path when picking materials is put forward and amathematical model with the material placing position as decision variable is built tominimize the path. The batching area layout and storage capacity of shelves are theconstraints. A second decoding method is proposed. The state transition rules isconstructed. Pheromone update mode of the ant colony algorithm is improved. Thestorage assignment layout of the batching area in multi-product assembly workshop issolved and optimized.(4) Combining the mathematical models established for showing the batching arealogistics process, optimization algorithms and the simulation model, a framework of asimulation and optimization system is proposed. A prototype system for simulatingand optimizing multi-product assembly workshop is developed. The storageassignment scenario and AGV scheduling scheme in the batching area of excavatorassembly workshop can be optimized and simulated in the system. The effectivenessand the correction of the model and method are validated.