Modeling And Optimization Of Energy Efficiency In Workshop

With environmental problems getting worse in the whole world, sustainablemanufacturing is being accepted as the peimary trend in manufacturing industry. As themajor energy consumer, workshop is poor energy efficiency, which generates highercost and serious environmental pollution. Study on energy efficiency in workshop issignificant and practical due to its great diversity and quantity of energy consumptionequipments with conplex energy characteristics. Therefore, the modeling andoptimization of energy efficiency in workshop is studied based on hybrid flow shop inthis paper.Energy consumption of workshop is mainly from machine tools, transportationfacilities and auxiliary equipments, which take electricity as primary power supply.Framwork of energy consumption in workshop is proposed and analysis againstmachine tool, Automated Guided Vehicle(AGV), lighting and Kanban is conducted.Savitzky-Golay Filter based processing nodes recognition method is proposed to obtainenergy consumption data of machine tools, which contributes to modeling of energyefficiency of workshop. Take AGV, lighting and Kanban as examples, data processingof transportation facilities and auxiliary equipments is conducted.Definition of energy efficiency in workshop is proposed according to the acturalsituation. Method of mathmatical modeling and simulation modeling aiming at hybidflow shop is proposed. Firstly, the constraints of modeling is given based on theprocessing and transportation features of wokshop including AGV. Secondly, takingprocessing path of workpiece and transportaion sequence of AGV as variables,mathmatical models of makespan and energy efficiency are established. Thirdly, basedon the simulation principle of discrete event dynamic system, simulation method isproposed to realize simulation of makespan, energy consumption of machine tools,transportation facilities and auxiliary equipments in MATLAB/SimEvents.Genetic Algorithm based weighted optimization and pareto optimization areemployed to solve bi-objective problem, which takes the minimum processing time andminimum energy consumption as optimization objectives. Real coded basedoptimization is used to discrible two different optimization variables. Tournament-random ergodic selection model is employed to select offspring population.Logical expression is applied to present selection process of pareto optimization.Case design following JB7741-95is performed to verify the proposed models andoptimization method. Optimization results of mathmatical model verify theeffectiveness of optimization method, besides, the results show that the percentage ofenergy consumption from machining is as high as70%-80%. Results of correlationanalysis on pareto front indicate that energy consumption of machine tools andauxilliary facilities is strongly correlated to total energy consumption and energyconsumption of transportation facilities displays no-correlation with total energyconsumption. Optimization results of simulation model confirm the the correctness ofenergy efficiency model At the end this chapter, analysis of advantages anddisadvantages between mathmatical model and simulation model is carried out.