Research On Multi-Objective Job Shop Scheduling With Double Flexibility And Prototype System Development

In the past few years,despite the rapid development of manufacturing informatization,especially in the development of manufacturing execution system,there are still problems to be solved.In particular,there are some limitations in the research of production scheduling module which is in the central control position of manufacturing execution system.Job-shop scheduling as a starting point,this study are that in the early study of FJSP,often because of the objective existence of some of the difficulties and ignore may exist in the process of scheduling constraints,including human factors are often ignored,however,human factors is actually indispensable elements of production system.Moreover,in the process of production,there is a huge demand for certain products,which emphasizes the production efficiency and ignores the related factors of green production.The unsolved problems above are the main reasons to prevent further development of China's manufacturing industry.In order to solve the above problems,the content of this paper is as follows:(1)In this paper,we originally propose a double flexible job-shop scheduling problem(DFJSP),in which both workers and machines are flexible.Because of the character of double flexibility,it conforms to the practical production better compared with the flexible job-shop scheduling problem(FJSP).In order to solve the DFJSP problem,a mathematical model of DFJSP integer programming is proposed to minimize the maximum completion time,minimize labor cost and optimize green performance.In the optimization of green performance,the effects of different machines and manual selections on energy consumption,noise,chip recycling and safety indicators were studied.(2)Based on the characteristics of DFJSP problems,a new hybrid genetic algorithm(NHGA)is proposed to solve the DFJSP problem.The algorithm designs three-layer chromosome coding and decoding methods which conform to the problem characteristics.It designs cross operators to ensure the feasibility of solutions and to obtain high quality progeny populations,at the same time,it designs mutation operator which can find out the best method to solve the problems.What's more,On the basis of the integration fitness ranking algorithm,it designed the adaptive integrated fitness algorithm.To obtain the best combination of the key parameters in NHGA,the Taguchi method of design of experiment(DOE)is used to evaluate them.Finally,comparisons with NHGA and NSGA-II shows that the proposed NHGA has advantages in solving accuracy and efficiency for the DFJSP,especially for the large scale ones.(3)Use the scheduling problems existing in the welding production of the truck crane jib structure as an application object.On this basis,a scheduling system model with multiple resource constraints and multi-objective is constructed for discrete production,and use the NHGA algorithm to solve it.Finally,a workshop scheduling prototype system including system management,basic data management,scheduling management and report output is developed,which realizes the transformation of the actual workshop scheduling plan to intelligentization,and improves the workshop resource utilization rate and production efficiency.