Research On Large Diameter Online Measuring Algorithm Based On Machine Vision And Error Model

With the rapid development of modern industry,the large diameter workpieces are applied widely,and the requirement of their diameter measurement has becoming higher, especially in the high precision measurement industry. To research the high precision measurement of large diameter is a current research hotspot, which not only can receive a high precision of diameter values, but also is important to other related industries, especially the online condition monitoring with the working security. We can obtain diameter of wheelset with the optoelectronic techniques and also get the wears of wheelset tread which has important significance to ensure the security of train travel.Firstly, the camera measurement principle and the calibration method are introduced. A multi-plane calibration method based on Zhang zheng-you calibration method are proposed based on the special geometrical relation between the camera and laser. This method can meet with the requirement of the camera calibration and also can provide a theoretical model for other related industries.To research the linear structured light center extraction method and can extract the center with sub-pixel.Then, proposes an improved calculating method for diameter measurement based on traditional hypotenuse-height method to meet the requirement of accuracy,which to avoid the larger error caused by the error amplifier principle from the traditional method.To set up a general experimental platform to perform the calibration experiment, diameter measurement, etc. The experimental platform not only can meet with the requirement of this experiment, but also can be used in the measurement of other surface.Finally, we established a GUI interface to make the experimental operation process simple after calculating the measurement results. To establish an error analysis model though analyzing the results respectively from the system error and random error.