Perpendicularity identification method of image-based welding of components

摘要

For the purpose of accurately inspecting and measuring perpendicularity of column elements on circuit board, a sub-pixel position technology-based perpendicularity identification method which combines centroid registration of edge contour is proposed. This method, first obtains element's pixel edge of pre-treated pictures using improved Canny algorithm, then rejects noise point and interference edge through edge track method and numbers the elements at last. The element's sub-pixel edge is obtained at the edge subject to crude extraction with the aid of Zernike moment algorithm. On the basis of this, the minimum circumscribed rectangle of the element's contour is obtained to correct the edge and get the areal coordinate. Perform registration between the centroid of the element on PCB board for test purpose and the standard centroid, so as to inspect and measure perpendicularity of each element according to displacement of the centroid. Experience has shown that the method mentioned herein can not only measure the welding skew but also is complete with high identification accuracy.