Research On Multi-objective Optimization For Work-Shop Sustainable Scheduling And Improved Algorithm

Nowadays,environmental problems have become the focus of global attention in the face of energy intensity and deteriorating natural environment.In the context of global environmental protection and energy conservation,how to achieve green manufacturing is an urgent task in China as a manufacturing power.As an important part of manufacturing system,production scheduling can improve the production efficient,reduce costs and energy consumption through reasonable scheduling scheme optimization system,so as to realize green manufacturing and energy-saving.This paper focused on the energy consumption optimization of workshop scheduling,studied the multi-objective scheduling optimization problem of the flow-shop and flexible flow-shop from the perspective of the enterprise's benefit and the government's environmental demand,and modified genetic algorithm were proposed based on the performance of machine tools.Specific contents are as followed.(1)With the increasing pressure of production efficiency,economy and environment,this paper focused on the flow-shop establishing a multi-objective model of the time,cost and energy consumption,and genetic algorithm was used to solve the problem to get the optimal scheduling scheme.Traditional workshop scheduling method is unable to meet the comprehensive demand of manufacturing process,and the workshop scheduling need to adjust the production strategy to keep pace with those requirements.This paper,focusing on the flow-shop established a multi-objective model of the time,cost and energy consumption,optimized the flow-shop scheduling problem by normalization and weighting methods.And setting up a flow-shop scheduling optimization method of high efficiency,low-cost and energy-saving,the index weights are calculated by the way of the analytic hierarchy process according to the production requirements which was accessed to conform to the present production situation of scheduling optimization,and genetic algorithm was used to solve the problem to get the optimal scheduling scheme.Based on this,four kinds of typical workshop production scheduling models were provided according to the characteristics of workshop production,and the sensitivity analysis is suggested to judge the workshop production mode.Finally,a case study was conducted to verify the practicality of this model.(2)A multi-objective optimization sustainable scheduling model was proposed for flexible flow-shop,the performance of the machine tools in hybrid-shop were described with fuzzy membership method and lay a foundation for the research of the improved algorithm.Flexible flow-shop has a wide range of applications in the enterprise as an extension of the flow-shop,it is more complex and flexible.On the optimization of flow shop in part 1,this paper established the time,energy consumption and cost model facing the current government's demand for environment and the pursuit of economic benefits.In addition,high-efficiency,energy-saving and low-cost performance of the machine tools were described with fuzzy membership method based on the analyze of different types of parallel machine tools,established the foundation for follow-up study.(3)In order to overcome the limitation of the traditional GA for solving the optimization problem of the hybrid flow shop scheduling problem,the performance of the machine tools are put into the solution of the genetic algorithm to improve it.Three layers of coding methods based on work,process and equipment are proposed.The adaptive crossover,mutation and elitist strategy were established to control the population trends.In the process of genetic algorithm,the matching state between the membership degree of machine tool processing characteristics and the weight coefficient of the scheduling target are adopted,the selection pressure to the proper direction can be obtained so as to accelerate the convergence speed in the iteration of GA.Finally,the weight of the objective function is selected by simple lattice design method,a case study was used to verify algorithm by comparing the results obtained by different GA methods.Based on the optimization results,four kinds of typical workshop production scheduling modes,including high efficiency,energy conservation,economy and comprehensive production were put forward to provide guidance for the sustainable production of hybrid flow-shop scheduling.