Position information detection technology of SRM skirt end face joint hole based on 3D point cloud

To address the issue of insufficient high-precision detection approaches for the spatial geometric coordinates of docking threaded holes on the skirt end face of solid rocket motor (SRM), which affects the assembly quality because the accuracy is solely ensured by the machining process, a rapid detection method for the position information of the docking threaded holes on the skirt end face based on 3D laser scanning technology is proposed. Firstly, an automatic tracking and scanning system was constructed by using a robot-driven 3D laser scanner to obtain the high-precision 3D point cloud of the skirt end face. Secondly, an improved moving least-squares (MLS) method based on KD-tree was used to optimize and process the point cloud to improve the accuracy of feature fitting. Finally, reverse modeling was carried out on the skirt end face of the 3D point cloud. After registering the reverse model of the skirt end face with the 3D point cloud, the relevant dimensions were quickly and automatically detected. The results show that the range of the six repeated test data is within 0.0293°. Taking the average value of the six groups of test data as the true value, the data deviation is within 0.0211°, and the RSD is less than 1%, which meets the requirements of engineering applications.