Research On Visual Monitoring And Application Method Of Ship Assembly Welding Production Line Based On Digital Twin

In recent years,with the rapid development and popularization of new-generation information technologies such as the Internet of Things,cloud computing,big data and 5G,a new wave of technological innovation in the manufacturing industry has been set off.For discrete shipbuilding enterprises,automatic welding assembly of shipbuilding is an important processing link,and it is also developing towards the direction of visualization,digitalization and intelligent technology innovation.As an emerging theory of technological innovation,digital twin is quasi-real-time digital mirror production line,which can show huge technical advantages in terms of transparent production and efficiency improvement.However,for the visual monitoring of the assembly welding process,the ship companies still use the traditional external camera fixed-position monitoring method,which makes the production line have a monitoring blind spot.The monitoring data of the assembly manufacturing process cannot be fully recorded,resulting in data missing and messy phenomena.In terms of monitoring data application,a normative data management approach has not been established.The monitoring data is presented in charts,which is not highly visible and impedes the further utilization of monitoring data.The production lines visual monitoring has problems of one-sidedness and limitations,and the development needs of ship intelligent manufacturing are severely restricted.Therefore,a visual monitoring and application method based on digital twin is proposed for ship production line.The construction of ship production line digital twin model,the design of the ship production line IOT system,and visual monitoring and application of ship production line based on digital twin are emphatically expounded.The research content of the thesis are as follows:(1)The digital twin model of ship assembly welding production line is constructed.Firstly,the manufacturing resources of the production line are analyzed,and the UML unified modeling language is used to construct the physical data model of the production line from four aspects: parts,equipment,buffers,and information.Secondly,the modular concept is used to construct a comprehensive production line description model.The geometry and behavior information of the model is encapsulated in a special model library,and its logical behavior is described by a control language,three sub-description models of configuration model,behavior model and logic model are formed.Finally,a mapping mechanism for the physical data model and description model mutual integration is proposed,and the virtual presentation of the ship production line provides intuitive visual effects for monitoring.(2)The real-time monitoring data of the production line is organized and managed.The real-time monitoring data types of the production line are analyze,the IOT system framework of the production line is proposed,and its system structure is designed.On this basis,the key station monitoring data collection implementation method is proposed.Through preprocessing and classified storage of the collected monitoring data,the accuracy of the data is ensured,the data foundation is laid for the real-time monitoring and application of the production line.(3)The visual monitoring and application of ship assembly welding production line based on digital twin is realized.Firstly,the influencing factors of production line visual monitoring and production capacity are analyzed,and the method framework is proposed.Then,the realization method of production status and production information 3D visualization monitoring is presented.Finally,digital twin model is proposed to evaluate the production capacity of the production line,and an optimization method of production job planning based on genetic algorithm is designed by improving the initial population.The production efficiency of the production line has been improved to achieve the real-time monitoring data application purpose,and the construction of the production line visual monitoring has been improved.Based on the above research,the ship assembly welding production line of a shipyard is taken as the research object,a visual monitoring and application system platform for the production line based on digital twin is developed by Plant Simulation software,and the application verification of the method proposed in this thesis is conducted.By displaying the visual monitoring content and application results of the production line,the effectiveness and practicability of the method is proved.