Abstract: The visual system of gantry ion parts groove cutting platform is slow to recognize the cutting parts,inaccurate contour positioning information and mismatching. An efficient matching and positioning method combining Hu moment and image registration is presented. Firstly,the threshold segmentation algorithm is used to reduce the noise of the picture,separate the background and foreground of the part,identify the outline of the part,and realize the rapid matching of the graphic library based on Hu moment. Secondly,coordinate transformation is carried out on the read CAD graphics,and an initial value of rotation Angle is found based on the contour centroid,and a function model is established. The iterative optimal solution is optimized using the idea of genetic algorithm. Finally,the contour path of the CAD template is used to correct the positioning information of the contour of the part. The experimental results show that the proposed method can quickly and accurately search the corresponding parts from the CAD library and realize the positioning information correction,and the overall image error after correction is about 6 pixels.

Key words: positioning, pattern matching, graphic registration, part identification, precision