Integration Of Inspection And Machining For Large Complex Aircraft Skin Parts

Supported by the National S&T Major Project and the National Science Foundation, considering the demands of aviation enterprises, the technologies of inspection and machining for large complex aircraft skin parts are studied so as to solve the problem that parts may be cut more or less during the machining and if severe enough they may be scrapped, which caused by the deflection that arises from the forming error and the deformation of parts during the clamping between the actual surfaces and the theoretical surfaces. The main achievements of this paper are presented as follows:(1) A scanning path planning method of aircraft skin parts for inspection position adjustment optimization is proposed. The existing scanning path planning technologies of laser inspection methods failed to consider the position adjustment optimization during the inspecting, which reduces the inspection efficiency and accuracy. To solve the above problems, different scanning modes are compared and analyzed to choose the best one; The best inspection direction is determined based on the curvature variation of aircraft skin parts; The inspection angles of aircraft skin parts are optimized based on the genetic algorithm to calculate the best location. Based on above, inspection position adjustment will be optimized, which lays the foundation for aircraft skin part laser inspection.(2) An actual surface reconstruction method of aircraft skin parts based on the inspection data is studied. Noise points are determined and removed based on the deviation calculation between the inspection data to improve the reconstruction accuracy according to the study of the inspection data processing methods and the inspection data reduction methods. Some points are inserted based on the geometrical methodology in order to make the reconstruction accuracy can meet the requirement. A relational model between the number of inspection points and chord error is established based on geometric reasoning algorithm to improve the data processing efficiency, which make the inspection data reduce in two steps.(3) An integration method of inspection and machining based on features for aircraft skin parts is proposed. In order to address the issue that it is difficult to generate the tool path for aircraft skin parts which can meet the requirements quickly caused by huge deformation. A toolpath mapping method and a toolpath projection method are used to realize the toolpath generation based on inspection data according to the requirements of position precision, which can improve the efficiency of toolpath generation on precondition of assuring the position precision.(4) The results of the study are applied in the inspection and machining system for aircraft skin parts, the system has been used for inspection and machining of several aircraft skin parts in aviation enterprises.