The Research Of Precision Thread Image Measurement System

In this paper, the precision thread measuring system based on machine vision detectiontechnology have been developed and studied. The system in the precision of machine visionmeasurement function is large extension in order to verify the machine vision detectionsystem of high precision and fast speed of superior performance though the application ofmeasurement system analysis.Precision thread measuring system is based on optical instrument equipped with and theoptimization of high precision image processing algorithms to establish a set of imageacquisition and processing system. In the aspect of image acquisition because of the use ofLED collimating DC source, the system, using projection lighting system and linear CCD, getmeasure images. In terms of transmission, the system, using1394hot plug image acquisitioncard pin, makes full use of the resources and image acquisition card to directly call dynamiclibrary function for real-time acquisition and transmission of image. In the aspect of imageacquisition program design, our system completes the image acquisition and processing by asingle thread of step5for the camera driver.In the aspect of image processing, the use of Visual c#object-oriented development iscombined with Halcon image software to complete the measuring program in Visual Studio2010environment of image processing and data processing. First, the software system, bycollecting experiment, has carried on the digital image processing to thread the original image,including Gaussian noise here in addition to dry, graying color image, balancing processingmodified image and smooth edge, calculating the image binarization threshold. And then, wecoordinate transformation location and boundary are being carry on by the use of Gaussianinterpolation method for sub-pixel edge fitting to get high accuracy boundary data.In terms of data show, what the human-computer interaction interface are by using c#design can not only show the measurement data, but the acquisition processes. Imageprocessing algorithms are designed upon program entrance for providing convenience as tooptimization test. Results show that the research designing precision thread measuring systemwith real-time can carry on the on-line measurement precision of screw thread, satisfy themachine vision measuring system for high precision measurement requirements of smallparts.