Pellets Inspection System Based On Matrix CCD Camera

Surface defects is one of the important factors for quality control. With the development of science and technology, more and more strict standard was set for the quality control of any material, so a new demand for detecting techniques is necessary in any industry. Using machine vision technology to detect material defects is a new way. At the present time, among the detection methods, inspection method based on CCD device is becoming the main trend, because it has many advantages, like light, high degree of accuracy, especially, its scanning speed is very fast.In this paper, our examination object is pellets material using for making XLPE high voltage cable. Impurity in pellets can cause the damage of the high voltage cable during its early lifetime, and so, this limits cable's service life and its reliability, and also blocks its development trend to a higher voltage level. As a result, the number and size of the impurity in the cable material become the imprtant parameter for cable's quality measurement. How to defect the number and size of the impurity expediently, real time, and accurately is what people care about.In this paper, we try to use the machine vision technology to detect pellets material defects. We use CCD device as the fundamental optical components. We design the opto-electrical defection module to fit the demand of the inspection system, set up a effective data acquisition and transmission system to ensure the following research can make progress smoothly. Image data is send to the upper computer through IEEE1394 bus. For the upper-layer software, we adopt objected-oriented design and implementation. In the software,we realize these targets: designed proper arithmetic which fit for the image characteristics, found the defects, got the statistical number and size of these defects. High performance and high data transmission speed of CCD device, objected-oriented design and implementation during the upper-layer software designment, all these above ensure the expansibility of the system's hardware and software, enable the system to meet the demands of pellets inspection very well.