Research On Key Technology For Fuselage Automatic Assembly Based On Model Definition

As the most representative product, the aircraft has complex shape and structures, huge size, small stiffness and particularly-high requirements on fatigue property. Therefore, the assembly quality of aircraft is quite high, especially the join process of assembly is critical. For a long time, the part manufacturing and assembly with analog transfer is the core issue during the aircraft manufacturing. In recent years, with the development of three-dimensional digital design and manufacture technology, the technology of Model Based Definition(MBD) provides the foundation for the digital transfer of aircraft dataset. Meanwhile, the flexible and automatic assembly technologies become the effective technological means to guarantee the quick quantity production of aircraft. Those advanced technologies integration and intersect, which has deeply changed the traditional aircraft manufacturing mode. The key technology problems involved in the C919 fuselage assembly process is studied in this thesis. The principal results are listed as follows:(1) On the issues of aircraft digital modeling technology based on the model definition, the MBD model building method for aircraft assembly is discussed. First, the date organization form and define requirements of MBD datasets are mainly discussed and analysis the generating of the MBD datasets under aircraft collaborative design. Combine with the process application of the MBD based parts datasets and assembly datasets, the process application of the MBD datasets for aircraft assembly, such as the information extraction of automatic drilling and riveting hole site and the production of lightweight assembly simulation model, is presented.(2) For the requirements of the fuselage automated assembly, the flexible positioning technique based on parallel kinematic configuration is presented. By application of the position and orientation characteristic set, a parallel kinematic configuration design method of flexible positioning tooling that has multi freedom is put forward. The drive optimization is deduced based on screw theory and the Jacobi matrix condition number of parallel mechanism. Then, the position and pose adjustment performance of the flexible positioning jig is analyzed. This method has been successfully applied to the flexible assembly jig design process for C919 fuselage assembly and providing a new technical way for the realization of the flexible positioning in aircraft assembly.(3) For the drilling technical problems in the automatic connection of the fuselage, the automatic drilling technology of one-side pressure in aircraft assembly is researched; its primary process parameters are determined by finite element simulation analysis. One kind of drilling process parameter optimization methods based on the adaptive response surface technique is presented. A process test research, combined with the typical automatic drilling equipment system, is conducted, and the effectiveness of the method is verified by experimental results.(4) For a new form of Al-Li alloy material applied on the fuselage of C919, the automatic riveting technology of Al-Li alloy panel is researched. Based on the discussion of the riveting manufacturability of the aluminum lithium alloy material, a method of process control technology to intervene the concerted riveting that is applicable for the Al-Li alloy panel to automatically drill and rivet is proposed. Through a lot of technological tests, the automatic drilling and riveting technological parameters of aluminum lithium alloy required for satisfying the amount of interference are obtained, which provides the theoretical support for the formulation of related process specification.Based on the above key technology, the automatic assembly line of C919 fuselage is planned. The division of C919 fuselage digital assembly stand position, the digital simulation of fuselage assembly process, automatic drilling and riveting of the fuselage panel assembly, drilling and riveting system off-line programming algorithm are presented. The research of aforementioned technologies has provided technique guarantee for the C919 Manufacturing. The application practice shows that the aircraft automatic assembly technology of the model based definition is the important way to enhance the quality and efficiency of aircraft assembly.