Research On Scheduling System Of Digital Twin Marine Diesel Engine Processing Shop

With the proposal of Made in China 2025,more and more factories are turning to digital and intelligent direction.However,it is still insufficient in the Marine industry,especially in the intelligent management of manufacturing process.At present,although part of digitization and information technology has been completed in Marine diesel engine processing workshop,there are still great deficiencies in production process monitoring,workshop resource planning and workshop macro-control.To a certain extent,this results in the workshop efficiency reduction,insufficient utilization of resources and other problems.The digital twinning technology can monitor the operation of the workshop and realize the visualization of the workshop.Dynamic shop scheduling based on digital twin technology can coordinate shop resources,macro-control shop plan,materials and personnel,which plays an important role in improving shop efficiency and reducing shop energy consumption.Shop is a complex combination of multiple functions.Previous studies on shop scheduling have many problems,such as rescheduling response lag,single influencing factors and separation of machine tools and transport vehicles.Therefore,combining with the concept of digital twinning,this study proposed to monitor multiple factor disturbances in the workshop,such as machine failure,tool wear and product quality sub-standard,and construct a multi-factor scheduling twinning service system in the workshop.Combined with the international background of energy rise,the scheduling scheme was evaluated with two objectives of minimizing completion time and energy consumption,which can influence parameters flexibly.By introducing the digital twin theory,the timeliness and predictability of shop scheduling are achieved for machine fault prediction,tool wear prediction and product quality monitoring,and the machine tool task and vehicle transport task are jointly scheduled.Finally,with the help of shop data acquisition system and database,the digital twin system of shop scheduling is developed to realize the monitoring and regulation of the physical shop.The specific contents of this study are as follows:(1)According to the current status of Marine diesel engine processing workshop,the actual needs of the workshop are summarized,and the functional module design is completed according to the requirements analysis,so as to complete the application framework of the shop scheduling system and comb out the key technologies to be completed.(2)Complete machine tool monitoring and disturbance monitoring.Firstly,the twin physical model of the machine tool is constructed.Secondly,data acquisition and data communication are completed.On this basis,based on the improved GJK collision detection method to complete the collision detection between machine tool objects and the use of data-driven way to realize the model motion monitoring and data monitoring,finally based on BP neural network to achieve the online prediction of the tool data received life.(3)According to the actual processing situation of Marine diesel engine workshop,the joint scheduling method of machine tool and logistics is proposed,and the mathematical model of joint scheduling is constructed.Two scheduling schemes of backward rescheduling and complete rescheduling were completed based on genetic algorithm after workshop disturbance,and the optimal scheme was selected.(4)Using Unity 3D platform and Visio Studio 2017 language development platform to build digital twin shop scheduling system.The chart was drawn by Echarts and Flask.SQL Server is used to construct twin shop database.Pycharm was used to write the back-end intelligent algorithm.Finally,the database,virtual workshop and back-end services are integrated to realize the overall development in Unity 3D platform.