Research On Intelligent Manufacturing Workshop Scheduling Problem Based On Digital Twin

With the rapid development of the new generation of high-tech and the continuous change of the global manufacturing market demand,China’s manufacturing industry is constantly transforming and upgrading towards automation,digitization,and intelligence,and has gradually formed a new production mode with the main characteristics of multi-variety,small batch,short production cycle,and product customization,which puts forward higher requirements for workshop operation mode,process flow optimization,and production planning.The traditional flexible job shop has problems such as low automation,intelligence,and visualization,lagging production information,difficulty in data interaction between different production equipment,and poor dynamic response-ability.It is urgent to carry out digital and intelligent transformation.The digital twin has the characteristics of virtual-real mapping,real-time synchronization,symbiotic evolution,and closed-loop optimization,which makes it a key technology to help the digital and intelligent upgrading of traditional production workshops.In this paper,by building a digital twin system of the intelligent manufacturing workshop,the intelligent manufacturing workshop scheduling optimization problem and visual job simulation and state monitoring technology are mainly studied,which improves the automation,digitization,and intelligent scheduling level of production workshops.Firstly,the research status of related technologies and problems at home and abroad are reviewed,and the main research contents of this paper are clarified.According to the problems existing in the traditional flexible job shop,the design requirements and principles of the digital twin system in the intelligent manufacturing workshop are established.Based on the analysis of the composition of the intelligent manufacturing workshop system,the main functional modules of the digital twin system are designed,and the overall framework of the digital twin system of the intelligent manufacturing workshop is designed on this basis.Secondly,the construction process of the digital twin workshop virtual model is expounded from four aspects:geometric model,physical model,behavior model,and rule model.For the digital twin manipulator loading and unloading system,the binocular vision system and Arduino are used for data acquisition and processing.RabbitMQ is used for data communication between physical space and virtual space,and the visual operation simulation and operation status monitoring of the workshop are realized through data interaction between virtual and real space.Thirdly,aiming at the optimization problem of intelligent manufacturing workshop scheduling,considering the related constraints of workpiece batching,machine tool,and Automated Guided Vehicle(AGV),a mathematical model is established with the shortest completion time as the optimization objective,and an improved bi-level optimization.algorithm is designed to solve it.Aiming at the dynamic abnormal events in the production process,a dynamic rescheduling process driven by abnormal event twin data is designed,and the algorithm is verified by a case.Finally,the digital twin prototype system of the intelligent manufacturing workshop is designed and developed,which realizes the visual operation simulation and operation status monitoring of material in-out warehouse process,AGV transportation process,and machine tool processing process,as well as the dynamic rescheduling driven by workpiece batching,dual resource scheduling,and real-time event twin data.The effectiveness of the system and algorithm designed in this paper is verified through a case study,and the influence of different AGV configurations on the production cycle and equipment utilization rate is analyzed.