Research On Path Planning Of Scanning In Aircraft Wing Assembly

Digital measuring equipment can detect the shape and pose of aircraft assembly components accurately, acquire the evaluation of testing results quickly and ensure the aircraft assembly accurately. Digital measurement with large-scale and high-precision is a key to improve the efficiency and quality of aircraft assembly. T-Scan is moved by a machine to realize the automation of scanning measurement, which is an inevitable trend in aircraft digital assembly. Planning of scan path is a key step for automatic scanning and reasonable scan path can improve the quality and efficiency of scanning effectively. Based on the Digital Assembly System for Airfoil, this paper researches the scan path planning and its optimization after analyzing the scanning constraints and geometric characteristics of airfoil.The system composition and work principle of automatic scanning measurement system are introduced. Automatic scanning measurement system is an important part of the airfoil assembly system. The T-Scan installed on the NC machine is driven by the NC machine to complete scanning. An automatic scanning software is designed to coordinate laser tracker, T-Scan and NC machine, which can make the scanning process efficiently and orderlyThere are many disperse geometry characteristics such as wall, groove and hole edge during airfoil assembly and their different features are analyzed. Combined with scanning constraints such as scanning angle, depth and width, the overall optimal method based on different objects is proposed. To solve the combinatorial explosion problem caused by the scan order of wing skeleton,ant colony algorithm is used to optimize the scan path and the idle stroke is decreased.Direction-parallel scanning is the overall strategy for large-size continuous surface which is on the outside of the wing panel. Based on discrete points of surface, automatic tracking scanning and path optimization method is proposed. To obtain the sampled points, the digital discrete of panel skin is completed through off-line programming software. Least square method is used to generate track path of sampled points after analyzing the shortcomings of traditional track method such as linear and ladder method. Optimized by genetic algorithm, the path takes less scanning time because path length and the number of pose adjusting are reduced. The scanning simulation using electronic prototype module verifies the feasibility and efficiency of the scanning path. Combined with three-dimensional model of six-axis NC machine and end effector, the coordinate system of NC machine and T-Scan is established and inverse kinematics solution of CNC machine is completed. Inverse solution value of each axis read from off-line programming software can drive the movement of NC machine. An area collision method and a laser entity method are presented so that the movement interference and scanning feasibility can be detected. Simulation results show that the planned path can complete the scanning effectively.