Abstract: To get rid of the weaknesses of the traditional defect detection of the microgear, such as low accuracy, inconvenient online implementation, and liable to manmade interference, a new detection technique for microgear defect based on the image processing technology using the charge coupled device(CCD) as the image sensor and the support vector machine(SVM) was proposed. The brilliant back illumination was provided by a light emitling diode(LED) illuminating source, the digital image of the tested mierogear was collected by an A102FCCD digital camera and input into a computer by an image acquisition card. The original gray level digital image with noise was processed by the edge retention filter to reduce its noise, and segmented by the iteration threshold method and the Otsu dual threshold method, and the binary image was formed. The samples of the gear were collected and the sample fatures were extracted. A gear defect recognition model was built based on the SVM. The recognition accuracy is as high as 97.8%. The proposed technique is characterized by low cost, high relialility, good popularization, and easy online implementation.

Key words: mechanical manufacture and automation, image processing, defect detection, charge coupled device(CCD), support vector machine (SVM), microgear