Study Of The Rail Wear Measurement Method Based On Dynamic Template

Non-destructive testing of rail wear is a world difficulty. At presret, other countriesuse the method of matching between the measuring rail profile and the standand to obtainwear value. The disadvantages of this method are difficulty in template match or featurepoint match, large amount of calculation, slow speed of data processing and so on. Thispaper presents a new measurement method which can generate a dynamic standardtemplate based on the3-D measuring rail profile and calculate rail wear. It reduces theamount of calculation and improves the accuracy of rail wear.First of all, this paper describes how to build the model of calibration and realize3-Dreconstruction of the measuring rail profile. Laser plane of the structured light and theprojection matrix of the camera are combined to build a unied calibration model andcalculate the world coordinate of each pixel. Secondly, in order to improve the accuracy ofmeasurement, this paper describes how to define the quatity and the world coordinate offeature point. Because the touch area between wheel tread and flange and the head is onrail’s top surface and inner side, not the web or the lowest point of the head and the twoparts don’t produce deformation during running, so the arc center point of the web and thelowest point of the head can be looked as feature points. Thirdly, in order to realize thedynamic measurement, this paper also describes how to generate the dynamic template andobtain the values of vertical wear and side wear. The analysis of standand rail profile’sgeometric relationship helps to present the measurement method of rail wear based onfeature point and geometric property of the standard profile.The experimental results show that this method can quickly and accurately anddynamicly generate standard template, has high measurement accuracy and well stability.