基于双目视觉的连接pin正位度检测方法

Abstract

Position detection of connecting PIN on printed circuit board (PCB) is a vital link to ensure the electrical reliability of PCB, which mainly detects missing, collinearity, and height of PIN. In this study, a method for determining the position of the connecting PIN based on binocular vision is proposed to meet the actual needs of production. First, the intrinsic and extrinsic parameters of the cameras are obtained by binocular calibration, and the stereo rectification of images is achieved.Second, the relevant grid is constructed according to the previously provided arrangement information and relative orientation, followed by PIN missing detection using a change of the grid's gray threshold. Next, to achieve the collinearity detection of PIN arrangement, the feature corner points corresponding to the PIN in two camera fields of view are extracted separately. Furthermore, the threedimensional coordinates of the pinpoint are determined based on the disparity principle.Finally, a feature extractionbased PIN relative height detection approach is suggested to implement the relative height detection for PINs. The experimental findings support the effectiveness of the proposed method; the average elapsed time of PIN relative height detection is 125. 4 ms, the accuracy is 99. 535%, and the repeatable accuracy is within ±0. 05 mm.