Research On Rescheduling Problem Of Flexible Operation Workshops Based On Digital Twins

The flexible workshop will face various unexpected events that interrupt the production process,and needs to be rescheduled to adapt to the complex and changing workshop production environment and maintain efficient production.Therefore,the study of flexible workshop rescheduling is more in line with the actual needs of production and can better solve the actual problems of the enterprise.In the process of rescheduling,digital twin technology is invoked to detect,identify and quickly respond to dynamic events through real-time information interaction between physical and virtual workshops,trigger the rescheduling mechanism,and give a rescheduling plan in time to maximize the production capacity of the enterprise and realize the maximum benefit of the enterprise.Based on the above,this paper conducts research on the rescheduling problem of flexible job shop in Company X.The main research contents are as follows.(1)This paper construct a flexible job shop rescheduling model based on digital twin according to the actual situation of the assembly shop.Problem analysis is carried out for the assembly shop to propose an optimization plan,and a digital twin-based flexible job shop rescheduling model is constructed according to the actual situation of the assembly shop.The rescheduling model includes a mathematical model built with three optimization objectives highlighted by the assembly shop,twin data collection and construction of a digital twin shop rescheduling prediction and optimization strategy.(2)The third-generation non-dominated genetic algorithm is studied to improve the design of traditional optimization algorithms for the shortcomings in solving multi-objective scheduling problems.The traditional optimization algorithm has the defects of long solving time,insufficient local search ability and insufficient elite storage to fall into local optimality.In this paper,we design the improved NSGA-III algorithm to reduce the algorithm solution time by changing the population initialization strategy;improve the crossover operator to increase the diversity of offspring;improve the elite storage strategy to avoid falling into local optimal solutions;and set the adaptive variation probability to prevent the algorithm from premature maturity.Finally,the superiority of the algorithm is verified by several standard examples more suitable for solving the total assembly plant scheduling problem.(3)This paper design a digital twin assembly plant rescheduling simulation model for the assembly plant of Company X.Based on the background of the production line of the assembly plant of Company X,the mathematical model and the improved NSGA-III algorithm are encapsulated into the Plant Simulation software based on Matlab programming technology to build the digital twin scheduling simulation model.The digital twin assembly Plant Simulation model designed based on Plant Simulation software consists of three parts: database module,core algorithm module and user interface module.