TFT-LCD Multiobjective Scheduling Research Whit Learning And Deterioration Effect

The thin-film transistor liquid crystal display(TFT-LCD)production is a flexible job-shop scheduling problem,with the characteristic of re-entrant,parallel machine and expensive production equipment.At the same time,there is a wide variety of TFT-LCD products,and the different types of products have different processing technology,which also increases the difficulty of the scheduling.Short product life cycle in electronics industry,put forward higher requirements on production arrangement and delivery just-in-time.With the innovation of technology,reasonable production scheduling is particularly critical to reduce the production cost,shorten production cycle,and enhance competitiveness.Therefore,the study of TFT-LCD production scheduling is better to contain multiple optimization objectives,not only minimize the maximum completion time,but also minimize the workpiece delay time.In actual machining process,processing time will be shortened due to operator proficiency and machine running,but when the machine shut down to wait for the workpiece,it will weaken the degree of proficiency,this is called the deterioration effect.For example,some process require machine processing temperature to a certain extent,however,the machine shuts down and temperature decreases,it will need some time to reach the specified temperature for the production.But till now,studying about the deterioration effect is less,some research is only mainly aimed at single machine problem or flow shop scheduling problem,which is not about learning and deterioration effect of TFT-LCD scheduling problem.In this paper,we will study the learning and deterioration effect of TFT-LCD multi-objective scheduling problem,and analyze the degree of different variables effecting the result,this is of a certain theory value and practical significance.This paper firstly introduced the general situation of TFT-LCD production,process flow,the domestic and foreign research about the workshop scheduling problem?TFT-LCD scheduling problem,and introduced the domestic and foreign scholars on the development of multi objective scheduling.Multi-objective mixed integer programming model was set up according to the production process of TFT-LCD Module process.Adding chaos search mechanism with Fireworks Algorithm was used to solve the problem,and dual championship and dynamic elimination of Pareto non dominated solution set construction method was proposed,mixed chaotic search mechanism introduced can effectively improve the algorithm accuracy and avoid premature in local search,and the use of the proposed algorithm to solve the job shop bench mark problem confirmed the feasibility.Two stage encoding and machine processing time priority selection method was used to solve the flexible job shop scheduling problem,the workpiece was priority to be processed by machine with shorter processing time,this was used to solve Kacem standard problem to confirm the feasibility of encoding.Then,the paper used the previous proposed algorithm to solve the actual case of TFT-LCD module process,and find out the reliable scheduling scheme in the actual production,and compares it with other algorithms.Finally,the model was established to study the learning and deterioration effect,and analyze the effect of different learning rate and deterioration effect on the completion time,when the learning rate is reduced,the time of completion,waiting time of the machine and delay time of workpiece will be shortened.