Study On The Online Measuring System Of Ceramic Tile Geometric Size

The online measuring system of ceramic tile size is on the basis of visual measuring. It is an equipment of detecting the geometric size of tile which integrates application optics technology, electronics technology, computer technology, accurate measuring technique.The equipment is used to measure the ceramic tile size on-line, including detecting the value of side length, straightness of fringes, diagonal and diagonal difference (D-value). It can solve the problems to a great extend which occur during the mass production of tile, such as the low-speed of manual detection, sizable errors, different precision level, large labour quantity etc. Making use of the real-time online measuring to report changing of the tile size in order to adjust the manufacturing facility's parameters and increase the product quality. At the same time, according to the graded size range set, the equipment can classify the products and guarantee that the size of products will meet to the requirements completely.The equipment is based upon machinery visual principle. It utilizes double linear CCD cameras to scan the tile's image which is passing through the camera's photographing area, then calculates all the tile's size parameters by appropriate arithmetic in order to differentiate if the products correspond in all respects with quality. Once it detects defective products, the alarm system will give an alarm. As following, the measuring system will reject the imperfections from production line and keep a record of the defection in computer as to stat and analyze. The whole process is not affected by artificial factors, having high stability and repeatability.This subject is developed by College of Precision Instrument Tianjin University and South China Institute of Precision Manufacture. This paper contact disciplines trends and the needs of practical application, studies the linear CCD large area scanning technology, the online measuring system of ceramic tile size based on computer vision is designed. The paper main contain includes:1. The online visual measuring system with the linear CCD at the core is designed. As the same time, it defines the scan and the control structure of machinery transmission synchronization. The prototype has completed and that has delivered to the company for trial. 2. It studies about the linear CCD scanning technology of large dimension and image collecting technology, also designs the linear LED light source which is apply to the system.3. It studies the image processing algorithm which is needed to collect the dynamic image with huge data size, including solving the contradiction problem between the high precision measuring principle and low precision mechanism transmission equipment and measurement errors which bring out by the thickness differences of tile's sides.4. It introduces an effective system demarcating method aimed at the actual production circumstance and national standards.5. According to the actual measuring requirement of the tile production company, it completed the compiling works of the measuring and controlling software.6. It conducted a large number of experiments on repeatable precision, value precision and measuring stability. It also analysis the errors source comprehensively of the tile online measuring system.