Vision measurement for flat parts based on local line-angle contour segmentation

In order to detect the size information of complex flat parts, this paper proposed a method for flat part measurement based on local line-angle contour segmentation. After processing the images taken by photos and edge detection, we obtained sub-pixel part contours. Then, the local line-angles of the part contours were calculated, processed and analyzed, and so on the features of the connection between the geometric primitives of different line segments on its contour were obtained. The segmentation of the part contour came true. Next, a line segmentation error model was built, and then we got the parameters of the contour segment and the key points of the components by iterative fitting the segmented line and pinpointing the location of the segmentation. Afterwards a binocular vision model provided the spatial point cloud of the key points. As a result, the size information of the parts were acquired after analyzation and calculation. The present method can successfully measure the multiple size of the complex flat parts, which is more efficient and precise.