Abstract:

The 3D measurement and evaluation of aircraft assemblies can provide critical data in the manufacturing process for quality enhancement. It is a complicated task to measure a complex aircraft structure during manufacturing with the requirements of no auxiliary equipment for the measurement, no influence on the assembly process, and numerous other restrictions at the site. Difficulties in the task include measure the object in various ways, realize data alignment with low accumulation error, and get data from obstructed areas. In this paper, we propose an integrated metrology approach which combines photogrammetry, structure light scanning and optical tracking measurement with a handheld probe. The data from the three types of optical measurement is unified into one coordinate system by using some designated reference points. In order to achieve high accuracy in aligning the measurement data with the CAD model, the principles for choosing the registration points are proposed based on the theory of sensitivity analysis. To demonstrate the validity of our method, an aircraft fore fuselage is measured, and the data registration using our proposed principles is performed, which shows that our method is valid and it produces accurate results for the in-process quality evaluation of complex aircraft assemblies.

Key words: digital metrology, aircraft assembly, visual reference point, data registration, registration point