Research On Scheduling Problem Of Ship Pipe Fittings Processing Workshop Based On Digital Twin

With the development of high-tech information technology and in order to meet the changes in market demand,intelligent manufacturing has also emerged and gradually developed and implemented.In order to effectively adapt to the dynamic changes in market demand,the shipbuilding industry is gradually moving towards an intelligent manufacturing model.The digital twin is one of the important methods to realize intelligent manufacturing.With the help of digital modeling,sensor perception update and other technologies,the realtime interaction and fusion of physical entities and virtual workshops can be realized.The pipe fittings processing workshop is one of the important production units in shipbuilding.During the shipbuilding process,it needs to process many pipe fittings of different specifications and models.The production man-hours account for about 8%-12% of the total man-hours of shipbuilding.65% of the processing time.At present,there are problems such as insufficient real-time performance,lack of interactivity,and insufficient integration with production data in the scheduling of ship pipe fittings processing workshops,and the collection and integration of a large amount of real-time data and diversified technological processes when applying digital twin technology.A more accurate and real-time model can accurately display various changes and influences in the production and processing process.By studying the scheduling of pipe fittings processing workshops under the digital twin,it is possible to connect information flows such as plans and production processes,and use data to drive virtual workshops in the process of production organization to simulate the matching relationship between the entire production plan and process requirements and other factors.Managers provide the most direct reference plan.The main research content of this thesis is as follows:Through the fusion of digital twin technology and ship pipe fitting processing workshop,a mapping framework based on digital twin for ship and pipe fitting processing workshop and pipe fitting processing workshop and scheduling is proposed.The framework can effectively integrate and transmit the data of ship construction and production scheduling with the production data of the pipe fittings processing workshop,so as to solve the problems of complex process flow and information asymmetry in the traditional pipe fittings processing process.The real-time mapping between the physical workshop and the virtual workshop is realized,and based on the output data of the virtual workshop,it assists the real physical workshop to make corresponding adjustments,thereby reducing production costs and improving workshop production efficiency.Based on digital twin technology and model-driven theory,a digital twin scheduling method for pipe fittings processing workshop of A shipyard is proposed,which can realize real-time interaction and iterative optimization between virtual space and physical space,so as to help realize efficient,flexible and reliable meeting of different requirements of A shipyard.Pipe fittings machining needs in shipbuilding of all types and sizes.At the same time,in order to shorten the production time,speed up the response to the demand of the downstream production link,reduce the occupation of the work in progress and balance the utilization rate of the machine,establish a pipe fitting processing workshop based on minimizing the maximum completion time,minimizing the maximum load of the machine and satisfying multiple constraints scheduling model,an improved genetic algorithm is designed as a solution method.The algorithm ensures the diversity of the population when selecting individuals,adopts dynamic probability to adapt to the optimization needs of different stages during crossover and mutation operations,and considers multiple objective functions and constraints when evaluating individual fitness,thus improving the algorithm’s performance and efficiency in solving multi-objective optimization problems.By using Simio simulation software,a virtual model is constructed to input the generated scheduling plan and constraint information such as processing time,the virtual model can perform virtual-real interaction and simulation verification,and reflect the improvement effect of the real-time and accuracy of the scheduling plan based on digital twins.And the optimized maximum completion time is reduced by 10.19% on the basis of the original processing cycle and the machine load is balanced.At the same time,the real-time and interactive nature of the scheduling process is increased,so that the continuity of production and processing and the linkage of production organization and management are strengthened.Therefore,the scheduling scheme of the ship pipe fittings processing workshop based on the digital twin has certain guiding and reference significance for the actual production of the enterprise.