Research On Hybrid Flow Shop Scheduling Method Based On Improved Fruit Fly Optimization Algorithm

Hybrid flow shop scheduling problem(HFSP)is a more flexible job shop scheduling model in production scheduling.which is widely used in different industrial development,such as steelmaking,textile,assembly and manufacturing.Because the machine can be selected in all stages of processing in HFSP,the complexity and flexibility of the problem are greatly increased,which belong to the NP-Hard problem.In the actual production process,the processing environment and constraint conditions are more complex.It is important to choose suitable methods to solve the HFSP under different constraints.The paper studies the two types of HFSP extension problems with no-wait and lot streaming respectively.With the Fruit Fly Optimization Algorithm(FOA)as the main technical means,an efficient intelligent scheduling optimization algorithm is proposed with the combination of the problem features.Firstly,based on the mathematical model of HFSP,the characteristics of no-wait HFSP and HFSP with lot streaming are analyzed,and the research framework of HFSP is put forward,which lays the foundation for the follow-up research.Secondly,the mathematical model of no-wait HFSP with unrelated parallel machine is set up,and an improved FOA algorithm based on double population cooperation mechanism is designed.Based on the feature of the problem,the two-layer encoding method and the decoding method based on the difference translation are used.In order to improve the diversity of solutions,combined with the adaptive step length classification search strategy and the variable neighborhood search strategy.The results of different sizes of numerical experiments prove the superiority of the improved FOA algorithm for solving no-wait HFSP.Thirdly,a mathematical model of HFSP with lot streaming which considering the sequence-dependent preparation time is set up.The improved FOA algorithm is used to solve the problem.The mutation operation of the genetic algorithm is introduced to improve the local search ability of the algorithm,and the effectiveness and superiority of the proposed algorithm relative to the other algorithms is proved by the simulation experiment.Then,in view of the problems existing with the lot streaming production process of machine workshop cylinder,the theoretical research results of the HFSP with lot streaming are applied.The experimental results prove the feasibility of the established mathematical model and the improved FOA algorithm in solving the actual scheduling problem.Finally,the whole work is summarized,and puts forward several directions for further research in the future.