Job Shop Scheduling Method For Bogie Assembly Under Multi-resource Constraint

Due to the fierce market competition pressure and the introduction of strict quality standards,the development of major rolling stock companies is facing more and more challenges.As an important part of production scheduling management of enterprises,job shop scheduling has received more and more attention.This paper takes the job shop scheduling problem for bogie assembly under multi-resource constrained as the research object,and successively studies the scheduling problem under certain working hours and random working hours.The main content is as follows:(1)Based on the analysis of the structural characteristics and assembly process characteristics of the bogie,use the processing technology network to express its production process,use the forward process relationship matrix table to express its process priority constraint relationship.And further based on the uneven distribution of station,worker,and overhead travelling crane resources in the bogie assembly process,job shop scheduling problem models for bogie assembly under multi-resource constraint with fixed working hours and random working hours have been established.Among them,by introducing two uncertain parameters to describe the fluctuation level and the constraint violation’s degree of random working hours,the robust optimization method is used to obtain a robust peer-to-peer model with random working hours obeying the normal distribution.(2)In the design of genetic algorithm,in order to avoid affecting the performance of the algorithm,and to accurately express the resource information,firstly,for job shop scheduling problems under fixed working hours,this paper designs a coding method for the repeated expression of process genes.Secondly,in order to avoid destroying the above coding expressions,the concept of gene blocks was introduced to solve the infeasible solutions that may occur during genetic operations.In addition,a repair algorithm was designed to repair the chromosomes that did not meet the priority constraints of the process after genetic operations.Finally,a decoding algorithm for resource space time is designed.On this basis,for the scheduling algorithm under random working hours,the uncertainty parameters of random working hours are further encoded into the chromosome,so as to achieve true "randomness".Combined with the advantages of variable neighborhood search algorithm in local search optimization,it is integrated into the proposed algorithm.(3)In order to test the efficacy of the proposed algorithm,the above method is applied to an actual engineering project.The scheduling schemes of certain working hours,random working hours and existing are analyzed.Finally,it shows the effectiveness of the proposed algorithm.