Study Of The Visual Inspection System For The Rubber Roller

The rubber roller is an important part of imprinter so there is a great impact for the quality of presswork. If the diameter, cylindricity and beat error of rubber roller don't reach the precision, it will result in that the presswork color isn't well-proportioned or appear with splashes. The traditional method to measure diameter, cylindricity and beat error is contact mode. The method doesn't adapt to measure the rubber roller because of the printing roller covered with the soft latex, and that these contact measurement instruments are expensive and require the condition well. Therefore, we need to study a method that suffices non-contact measurement and appropriate precision.According to the material characteristic of the rubber roller, a new method about using visual detection technology to measure the form and position error of rubber roller is proposed in this paper. In the visual inspection system, the image was collected by the digital CCD camera, and was input into computer by the digital interface card. The software of system is developed on LabVIEW 7.1 and IMAQ Vision as exploitive tool. After pretreatment such as image smoothing, image enhancement and edge detection, according to the arithmetic of form and position error calculate pixel value of diameter, cylindricity error and beat error. Finally, the result of measurement is transformed from pixel value to real value by system calibration. The method of non-contact measuring rubber roller has been validated successfully by a great deal of experiments.Integrate virtual instrument and visual detection technology to bring into full play their respective predominance, shorten the development cycle of the system, and enhance reliability and expansibility. Traditional detecting methods have a lot of defects, for example manual detecting is low efficiency, low accuracy, and a great many measurements can not meet the on-line detecting requirement. This system can solve these problems so it has a bright future, and that there is the reference value to inspect other columned objects.The paper includes the following several parts:(1) According to the material characteristics, shape and the accuracy requirements of rubber roller, design the overall system and hardware configuration. (2) Based on the LabVIEW software development platform, analysis features of the image processing function in the IMAQ Vision software package. Process images using filtering, image enhancement, edge detection and other technologies and means, and compare the effects of image processing to determine the best processing method.(3) Determine the image measurement method and image processing arithmetic. Include that detect image the coordinates of sampling point for calculating the rubber roller diameter; calculate the cylindricity error by the least square method; based on laser diffraction theory to measure diffraction fringes for the beat error; obtain the actual measurement results by system calibration.(4) Complete the software system design to collect image on real-time in the experiment, assess the diameter of rubber roller, cylindricity error and beat error any more analyze systemic error.