Research On Axle Vision Measurement Technology Based On Optical Probe

Rail transit is an important means of transport. With the rhythm of life to speed up the railway transport speed is faster and faster, which makes a higher demand for the production of its parts. Train wheel is the key components of the train and the rail link, and the use of axle between the wheels to connect, so the processing accuracy of the axle determines the safety of railway transport.In this paper a detailed analysis of the monocular visual measurement principle and considering the measured characteristics of the motor car axle, using probe measured axis point information and then fit the perpendicular to the shaft centerline cylindrical section, axle length of radius measurement. The vision measurement system is composed of CCD camera, optical probe, image acquisition card and computer. When the measurement is made, by the optical probe measured axle on the three-dimensional coordinates of the point to be measured, and deal with the income of the shaft end of the pasta and shaft, fitting. Finally a vertical section of cylindrical axle radius length.The optical measuring head position of characteristic point information, according to the camera’s perspective imaging model measurement model of the system, measured the position and pose transformation relation matrix between the head frame and the camera coordinate system using the orthogonal iteration algorithm for solving, then use obtained from the Rotary Peace transition matrix for a test head measuring tip in the camera coordinate system of coordinates. In order to improve the measurement accuracy of the vision measurement system, this paper uses the method of double three interpolation Gauss surface fitting to realize the sub pixel localization of optical feature points.Using vision measurement method in this paper, we study on the car axle radius length were measured, the analysis results show that: research articles of measurement based on optical head axle vision measurement method is feasible, and the measurement error range: ± 0.03 mm.