As a visual inspection technology, image measurement technology needs to realize quantitative measurement. Measurement accuracy has always been an important index pursued by this technology. Image measurement systems usually use image sensor devices such as CCDs to obtain image information, convert them into digital signals and collect them into a computer, and then use image processing technology to process digital image signals to obtain various images required. Calculation of size, shape and position errors is achieved by using calibration techniques to convert image size information in the image coordinate system to actual size information.
In recent years, due to the rapid development of industrial production capacity and the improvement of processing technology, a large number of products of two extreme sizes, namely large size and small size, have appeared. For example, measuring the external dimensions of aircraft, measuring key components of large machinery, EMU measurement. Critical dimension measurement of micro-components The trend towards miniaturization of various devices, measurement of critical micro-dimensions in microelectronics and biotechnology, etc., all bring new tasks to test technology. Image measurement technology has a wider measurement range. It is quite difficult to use traditional mechanical measurements on large and small scales. Image measurement technology can produce a certain proportion of the measured object according to the accuracy requirements. Zoom out or zoom in to accomplish measurement tasks not possible with mechanical measurements. Therefore, whether it is super-sized measurement or small-scale measurement, the important role of image measurement technology is obvious.
In general, we refer to parts with sizes ranging from 0.1mm to 10mm as micro parts, and these parts are defined internationally as mesoscale parts. The precision requirements of these components are relatively high, generally at the micron level, and the structure is complex, and the traditional detection methods are difficult to meet the measurement needs. Image measurement systems have become a common method in the measurement of micro-components. First, we must image the part under test (or key features of the part under test) through an optical lens with sufficient magnification on a matching image sensor. Obtain an image containing the information of the measurement target that meets the requirements, and collect the image into the computer through the image acquisition card, and then perform image processing and calculation through the computer to obtain the measurement result.
The image measurement technology in the field of micro parts mainly has the following development trends: 1. Further improve the measurement accuracy. With the continuous improvement of the industrial level, the precision requirements for tiny parts will be further improved, thereby improving the accuracy of the measurement accuracy of image measurement technology. At the same time, with the rapid development of image sensor devices, high-resolution devices also create conditions for improving system accuracy. In addition, further research on sub-pixel technology and super-resolution technology will also provide technical support for improving system accuracy.
2. Improve measurement efficiency. The use of micro-parts in the industry is growing at the geometric level, the heavy measurement tasks of 100% in-line measurement and production models require efficient measurement. With the improvement of hardware capabilities such as computers and the continuous optimization of image processing algorithms, the efficiency of image measuring instrument systems will be improved.
3. Realize the conversion of the micro-component from the point measurement mode to the overall measurement mode. The existing image measuring instrument technology is limited by the measurement accuracy, and basically image the key feature area in the tiny component, so as to realize the measurement of the key feature point, and it is difficult to measure the entire contour or the entire feature point.
With the improvement of measurement accuracy, obtaining a complete image of the part and achieving high-precision measurement of the overall shape error will be used in more and more fields.
In short, in the field of micro-component measurement, the high efficiency of high-precision image measurement technology will inevitably become an important development direction of precision measurement technology. Therefore, the image acquisition hardware system has obtained higher requirements for image quality, image edge positioning, system calibration, etc., and has broad application prospects and important research significance. Therefore, this technology has become a research hotspot at home and abroad, and has become one of the most important applications in visual inspection technology.
Post time: May-16-2022