Research on the size of ring forgings based on image detection and point cloud data matching method

The outer dimensions and 3D model of ring forgings in industrial production are the important parameters to ensure the quality of the products. In order to realize the measurement of the outer dimensions and 3D model of the ring forgings, a measuring method for the ring forgings combining with a CCD camera and a 2D laser scanner is proposed in this paper. Firstly, the image information of the ring forgings is obtained by the CCD camera. The radiuses of different sections for ring forgings are acquired by pixel calibration and edge detection. Secondly, the point cloud data of different sections are obtained by laser scanner with the movement of the transmission mechanism. Then, the position discrimination method of straight line fitting is used to reduce the error data. And the radius matching method is used in the further processing of the point cloud data based on image detection, and the point cloud data with high accuracy is further extracted. Finally, the 3D point cloud data and 3D model of the ring forgings are obtained by rotating the 2D point cloud data. The outer dimensions of forgings are derived from the 3D model. The experiments were carried out with two different ring forgings. According to the experimental results, the feasibility of the method proposed in this paper is verified.