The Research On Key Technologies Of Digital Production Line For Aerospace Product Shells

The shell parts are the core parts of aerospace products,which are characterized by complex structure and high processing accuracy.With the development of high-density demand of aerospace products manufacturing,the tasks of aerospace product shells gradually show the characteristics of multiple models and states,frequent changes,short development cycle,heavy tasks,high quality and reliability requirements,as well as the coexistence of development and mass production.It is urgent to change the manufacturing mode by means of digital and intelligent manufacturing.The thesis aims at the demand of intelligent management and control of production lines of aerospace product shells and tries to solve a series of problems in traditional production line mode,such as insufficient flexibility and fast conversion ability when dealing with the changes of aerospace product shell manufacturing tasks,inability to achieve precise production scheduling,inability to accurately predict production line capacity per unit time,inability to accurately predict production cycle and difficulty in quality management of products.Based on the above objectives,the thesis addresses key technologies of aerospace product shell digital production lines,including production line planning and design,intelligent scheduling and quality management & control.The addressed technologies are implemented in a large aerospace manufacturing enterprise in China.The main research contents are as follows:Firstly,according to the manufacturing characteristics of aerospace product shells,the key technologies needed to construct the digital production line for aerospace product shells are analyzed.The construction method of the aerospace product shell digital production line and its support system are designed.A digital production line system architecture suitable for the characteristics of aerospace product shells is proposed.Through the integrated application of material coding technology,material storage and automatic distribution technology,off-line clamping technology and tool management technology,the automation level of product processing process is improved.Also,material timely distribution and product life cycle location tracking are realized.The automation system of production line is established,and the production process of shell products automation capability is improved.Secondly,based on the construction of production line management and control system,the data architecture of manufacturing resources in digital production line and classification of production line operation design information have been put forward.Then,the overall technical structures of manufacturing execution system,data acquisition system and quality information management system of digital production line are analyzed as well.The centralized information control of production line from receiving production plan to completing the whole process of product delivery is applied successfully.Also,effective monitoring of various resources and rapid identification of production abnormalities are realized.Thirdly,the optimal scheduling problem under the multi-variety and small-batch production mode of aerospace product shells is investigated.Considering the constraints of the machine state,shift of the actual production workshop,etc.,the model of the actual production workshop scheduling is established.The improved evolutionary algorithm is developed to solve the problem.Thus,the reasonable arrangement of task procedures and the efficient use of equipment resources are realized.By considering the efficiency objective and the cost objective,the multi-objective model of mix-flow production is developed.A knowledge-driven multi-objective evolutionary algorithm is designed to solve the problem.Finally,according to the characteristics of the quality management of aerospace product shells,the data-driven quality control technology of the aerospace product shell production line is studied.The overall framework and data plan for the quality control of aerospace product shells are proposed.Four quality data collection methods based on data line transmission,digital equipment measurement data collection,on-machine measurement data collection and multimedia record online collection are studied to meet the needs of automatic collection of various types of data.The quality data application technology of the aerospace product shell production line is studied.And the programs for automatic monitoring,abnormal early warning,correlation analysis,quality information tracking and tracing based on quality data are proposed.A case study of the application of quality data was carried out.Based on the structural data and simulation data of a certain product,the criticality of product processing quality is analyzed,and a mathematical model of quality is established.The research results have important theoretical significance and practical value for enriching and developing the aerospace product shell digital production line’s planning,design and intelligent management & control.Also,the research results can promote the application of aerospace product shell digital production line construction.