| As the rapidly development of the railway, the requirements of safety and comfort are increasing. So the detection of railway infrastructure becomes particularly critical. Therefore, researching detection technology, which is sample, efficient and can be used in the railway field, becomes significance. Laser triangulation, as a conventional non-contact measurement technology, has no special requirement for the detected object and can be carried out in harsh environments compared to direct-detection technology. It is widely used in displacement, dimension, and angle measurement, for its simple configuration, high peed, high resolution, anti-interference ability and real-time processing capacity.In this work, an optical system for laser triangulation measurement system is designed and analyzed theoretically. The correction for the theoretical analysis and feasibility for the design are confirmed experimentally. The mainly content of this work includes:Firstly, the principle of optical system of direct-incident laser triangulation measurement is analyzed theoretically from laser triangulation measurement principle and practical measurement requirement. A measurement system, which consists of a semiconductor laser source, an imaging Plano-convex lens, and a high-speed linear CCD TCD1703C receiver, is designed. The measurement range and resolution for this system can be varied by adjusting related parameters.Then, a laser triangulation measurement system is built in laboratory environment. The high speed linear CCD photoelectric data are collected using the collection and transmission system based on the USB interface developed by the lab. In the experiment, system is calibrated by the corresponding relationship between the displacement variation of measured object and the pixel position of laser spot imaging on linear CCD. The results showed that, the minimum resolution is better than the 20μm in the range of designed measuring span, which is accord to the theoretical design expectations. |
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