A Three-Dimensional Shape Measurement for Large Deep-Cavity Parts

In manufacturing, it is important to measure large, complex, deep-cavity parts with high accuracy. Due to the large size of the part itself and the complex structure of its inner and outer surface, the traditional three-dimensional (3D) optical measuring system is more difficult to measure. In this paper, a collaborative measurement system for large-size complex deep-cavity parts is proposed based on high-dynamic range N-step fringe projection profilometry and parallel single-pixel imaging technology. By collaborative measurements, the 3D point cloud of internal and external surfaces of parts are reconstructed, and the measurement results are stitched. Experimental results show that the system can accurately measure the internal and external surface of complex deep-cavity parts and stitch the point cloud data with high accuracy.