Research on flange edge detection method based on reprojection transformation

Flanges are an important component in the industry, used for pipe connections and equipment assembly. Accurate edge detection is key to flange positioning and pose estimation. Traditional methods like Canny and Sobel are effective under ideal conditions, but they are difficult with complex backgrounds and noise. In this study, we propose a method to locate the projection plane by using the geometric constraints of bolt holes, and optimize the edge of the extracted flange based on the projection plane. Finally, the ellipse fitting of the extracted flange edge is carried out, and the ellipse fitting result is used to replace the flange edge, which ensures the continuity and accuracy of the extracted edge and realizes the extraction of the flange edge. Experimental results show that the proposed method has a significant effect on the edge discontinuity caused by noise and occlusion, and significantly improves the detection accuracy.