Application Of Computer Vision In Detecting Defects Of Small Ceramic Tubes

With applying computer technology to nondestructive detection area, the computer vision has become a vital embranchment, and the span-new application domain of nondestructive detection is exploited. Ceramic has many excellent performance, and it can be made into the parts and replace the traditional material, so it has a wide application outlook. But the fracture toughness of ceramic is very low and it is a typical brittleness material, so it is very difficult to control the quality of ceramic parts in batch production, especially in the production of small diameter and thin wall ceramic tube used for resistor. Therefore, it is of very significance to probe into question of detecting small ceramic tubes. At present, the small ceramic tubes are usually detected by naked eyes, this method is inefficient and laborious, and many factors such as the attention and stamina of the checker have effect on the checkout result. A method which computer vision technology is used to detect defect of small ceramic tubes is put forward, and the automatic testing system is developed by technologies of computer, computer vision, machine-electron and so on, and automatic detecting and classifying of small ceramic tubes are realized. The system comprises five parts which are the machine of automatically delivering and picking, PC, control unit, lamp-house, image collecting and processing. Image acquirement is fulfilled by CCD camera and image card. The detecting principle is that the part of the ceramic tube's surface with flaws present lower greyness than the part of eligible in irradiating of lamp-house, then we can determine whether the ceramic tube is eligible or not by the information of its image. In testing, first, small ceramic tube running, and simultaneously, shooting and storing the tube images by CCD video camera; and secondly, images are preprocessed, segmented, feature extracted and sorted; finally, the inferior is eliminated by the manipulator. Taking example for the semitransparent ceramic tube that external diameter is 8 millimeter and inside diameter 6 millimeter, the testing method of small caliber and thin ceramic tube is researched by the automatic system. The outcome of the experimentation accords with the fact, this method is simple and feasible, and is of high efficiency, dependability, and high automatization.