Axiomatic Design And Scheduling Optimization Of Virtual-real Interaction Fusion In Digital Twin Flexible Workshops

The digital twin workshop is a new intelligent manufacturing solution that enables intelligent control and continuous improvement of production scheduling through the integration of virtual and real interactions.Digital twin workshop relies on information technology to establish two-way connection and interaction between physical workshop and virtual workshop,dynamically update the twin model with the evolution of physical workshop,and combine virtual simulation technology and real-time data to simulate and predict the workshop production scheduling process,so as to timely find problems and adjust the production plan to ensure the smooth production of the workshop.However,the current digital twin workshop virtual-real interaction fusion in the practical application of low interaction efficiency,data fusion effect is poor,the twin model is difficult to accurately reflect the workshop state in real time,can not play a role in the continuous optimization of production scheduling.Axiomatic design is a design method based on logic and formal methods,which aims to ensure the accuracy and consistency of design.The study of digital twin workshop virtual-real interaction fusion based on axiomatic design theory can improve the efficiency and consistency of virtual-real interaction fusion,provide more accurate data and simulation for the continuous optimization of production scheduling,and further improve the workshop productivity and intelligent control level.To address the problem that the digital twin workshop cannot establish an effective virtual-real connection interaction,which makes it difficult to provide scientific decision basis and simulation for production scheduling,so as to realize intelligent production,this thesis carries out an axiomatic design for the virtual-real interaction fusion in the digital twin workshop.By analyzing the operation mechanism of digital twin workshop,the virtual-real interaction fusion is divided into four key functional requirements: virtual-real interaction,virtual-real mapping,digital-model linkage and interaction control,and relevant technologies and theories that directly affect the efficiency and accuracy of virtual-real interaction fusion are identified,such as workshop data collection capability,twin model establishment capability and data analysis capability,etc.;on this basis,a mapping hierarchy diagram is formed,which reflects On the basis of this,a mapping hierarchy chart is formed to reflect the complex interaction between the elements of the digital twin shop virtual and real interaction fusion.The study can provide a reference for enterprises to ensure the consistency and reliability of virtual-real interaction fusion in the digital twin shop under changing shop floor production conditions,and provide a more accurate and scientific decision basis for continuous improvement of production scheduling and continuous optimization of shop floor production processes.The digital twin workshop provides accurate data and simulation for production scheduling optimization through virtual-real interaction fusion,which facilitates managers to improve production bottlenecks and problems.In this thesis,the multi-objective scheduling optimization problem of digital twin workshop is addressed.Considering that the core equipment is the key equipment related to the normal operation of all processes and production lines,and its utilization rate can intuitively reflect the quality of the scheduling plan and the operation efficiency of the workshop,a scheduling model with the optimization objectives of maximizing the utilization rate of core equipment,minimizing the maximum completion time and minimizing the delay time is constructed in this thesis.The multi-objective optimization model is solved by NSGA-II with fast convergence and strong search capability.After analyzing the shortcomings of this algorithm,which has low population diversity and easily falls into local optimal solutions,the initial population is generated by a good point set and improved by introducing a congestion operator with variance consideration and an elite retention strategy with dynamic adjustment capability.The arithmetic study shows that the improved NSGA-II proposed in this thesis has good performance in reducing the maximum completion time and maximizing the utilization of core equipment,which can effectively improve the quality and efficiency of digital twin flexible shop scheduling.Finally,taking the diesel engine block machining workshop of Company A as the research object,the digital twin production scheduling application framework of this workshop is designed based on the mapping hierarchical structure diagram of the digital twin flexible workshop based on the axiomatic design proposed above,which provides a certain reference for the future digital twin transformation and upgrading of the diesel engine block machining workshop of Company A.Meanwhile,the multi-objective scheduling model considering the utilization rate of core equipment is applied to the actual production.The multi-objective scheduling model considering the utilization rate of core equipment was applied to the actual production,and the improved NAGA-II algorithm was used to schedule an order in May 21 and compared with the original production plan of this workshop.The results showed that the algorithm proposed in this thesis performed well in terms of maximum completion time and utilization rate of core equipment,which verified the effectiveness and feasibility of the model proposed in this thesis and the improved NSGA-II.