An automatic inspection method of welding precision for high voltage ceramic capacitor

Inspection of welding precision is important to ensure the quality of High Voltage Ceramic Capacitor (HVCC). The purpose of this paper is to propose an automatic inspection method which is used to check the parallelism and position after welding. The method is, firstly, capture images with the help of a CCD camera. Next, detect edge with Canny operator. Thirdly, use modified Hough transform to find circles for parallelism checking. Fourthly, execute the parallelism inspection in the way of comparing distance. Fifthly, use the least square method to ascertain circles for position checking. Last, execute position inspection in the way of intersecting circles. In experiments of three different sizes HVCC, the proposed method is proved to be very effective.