Development Of Non-contact Optical Measurement System Based On Virtual Instrument Technology

Along with the development of modern science and technology, non-contact optical measurement system based on the use of machine vision plays an important role in more and more areas, has become one of the most commonly used methods of 3d measurement in modern industrial manufacturing. Virtual instruments theory was established in 1980s, A machine vision system based on virtual instrument has largely solved the problem of the machine vision programming & difficulties of modifying and fully met the development requirements of machine vision to be faster、cheaper、more accurate & more reliable, becoming more and more economic & practical.Based on the military-industrial program "analog measurement in dynamic environment" and the applied technology "machine vision", this article put forward the non-contact optical measurement system according to virtual instrument technology in the actual measurement environment.The system uses the optical imaging technology to convert the coordinate of the product’s measured part from three dimensional measurement to two dimensional measurement, It acquires images with the help of CCD linear array driven by mechanical motion mechanism and optical sensor, identifies images using Lab VIEW software platform combined with digital image processing technology by computer, and convert Pixel coordinates into physical coordinates with Mathematical model. All theses steps lead to the success of the non-contact optical measurement, as a result of which, the final aim is fulfilled. The main contents of the essay are as follows:First, it introduces the significant measurement technology in machine vision---stereo vision technology and its composition、operational principle and working process. Also, it brings forward the implementation plans of the non-contact optical measurement system on the basis of virtual instrument technology.Second, it explains how to construct the machine vision measurement system on the platform of LabVIEW plus the image processing software packages.Thirdly, considering the qualities of system image acquisition, the module scheme to take images using virtual instrument is explained.Fourth, when designing the module of processing and analyzing images, to denoise and sharpen the acquired images at first, then match the images according to their coding values which are marked where it is a coding mark point, and finally work out the three-dimensional coordinates with the method of stereo vision technology.By means of the research in this essay, the model of the non-contact optical measurement system is formed based on visual instrument technology. Measurement on other aspects can be achieved without adjusting too much of the software system, which make full use of the advantages of virtual instrument measurement such as its composition convenience and wide adaptation to tasks, etc.