Improved comparison inspection algorithm betweenICT images & CAD model
改进的工业CT图像与CAD模型的比对检测

This paper improved an algorithm of analyzing the manufacture error based on comparison inspection between ICT images and the CAD model. Firstly, it segmented the ICT images by 3D Otsu threshold method, and then obtained the edge surface and corner features. Secondly, it calculated the oriented bounding boxes (OBB) of the ICT images' corner features and the work-piece's CAD model using the presented rotating projection method presented, then realized the rough registration by the two OBBs. Then the singular value decomposition and iterative closest point (SVD-ICP) algorithm were used to complete the precise registration between the CAD model and corner features of ICT images. The k-d tree was used to improve the calculation speed of searching for the closest point. Finally, it displayed the error using edge surface. The experimental results indicate that the result of rough registration in this paper is more accurate and applicable. The whole algorithm is more rapid and efficient.