Design Of Rubber Damping Pad Defect Detection System Based On Machine Vision

Machine vision inspection technology is a kind of technology which has the advantages of fast detection speed, high accuracy, simple operation and so on. The technology uses the image acquisition device to obtain an image of the object to be detected, then comparing the image with pre-set standards. The quality status of the detected object is determined consequently. In this paper, according to the object’s physical properties, optical properties,surface features and detection indicators, an automatic detection system of non contact object has been designed based on machine vision by taking automobile rubber damping pad as the research object, adopting CCD camera to attain images, and assorted with computer, hardware interface and software.Images captured from cameras have different degrees of distortion, which will affect the results of the subsequent image processing. In this paper, the camera calibration method was studied based on the model of camera imaging and the causes of the nonlinear distortion.Through from different angles on the black and white checkerboard figure and by finding corners, the internal and external parameters of the camera were obtained according to the correspondence between the object point and the image point. Distortion of the image can be corrected based on these parameters. In defect detection section, first of all, the distribution and processing flow of the image source was set up depending on the collecting station and the image acquisition characteristics, so that the image can be processed in parallel; Secondly,images of rubber shock pad were preprocessed. The image template matching method based on the combination of Harris corner feature and the image gray value was used to match the online template matching. Wavelet denoising method was used to deal with the inner wall of the through hole and image segmentation method based on edge detection was used to separate the target area from the background, preparing for defect identification; Finally, plana detection area according to the detection requirements and set a reasonable threshold according to the gray level histogram, which can accurately locate the defect parts and identify defects.In this paper, the defect detection equipment based on machine vision has the advantages of fast matching speed, strong anti-interference ability, accurate defect recognition and so on.The experiment result showed that the device can satisfy the requirements of online defect detection after repeated tests. At present, the actual equipment has been put into use, which improves the detection efficiency.