Positioning System for the Aircraft Structural Assembly

This paper presents a new conception of a positioning technology concept for aircraft structural assembly, for instance the manufacturing of the fuselage sections from shell panels and floor grids, the alignment of the sections to build the fuselage, and the joining of wings and tail units to the fuselage. The positioning system features a modular, reconfigurable, and versatile solution for various aircraft dimensions and different applications. It provides the customer with a holistic solution that considers the positioning task taking into account the operation conditions and the environmental influences within the very same control unit. The positioning system consists of three main modules that communicate over a standardized interface: A large-scale metrology system for an accurate identification of the positions and orientation of the aircraft components, a mechanical system for the handling of these components and a control system. The latter is the core module of the positioning system. It ensures a synchronous driving of up to forty-eight (48) axes and thus guarantees the proper handling of the aircraft components by no deflection during the assembly process. Highly efficient strategies and robust algorithms for the compensation of mechanical and thermal effects are embedded within the control system and guarantee high positioning accuracy. In performance evaluation tests within the project A350 XWB, an absolute accuracy less than (+/− 0.1mm) and a repeatability less than (+/− 0.05mm) for the positioning of large shell panels measuring almost 20 meters by 6 meters could be reached.