Research on Calibration Method of Rail Profile Measurement System

Abstract

The rail profile measurement system is used to obtain the full section profile of the rail, which is the core of the wheel/rail interaction, based on the principle of infrared structured light. The system calibration is the key as to whether the accuracy is high enough to guide the railway maintenance. In this study, we propose a convenient and efficient checkerboard plane target calibration method based on the partition-based calibration. This method can theoretically solve the three unavoidable factors that affect the accuracy in the traditional method and is very easy to use in the field with the designed equipment. The test shows that this method has higher accuracy. We propose a correction method for the stitching calibration of double-sided cameras. Based on the standard block and high-precision stitching of rail, full section profile is achieved. Finally, through ingeniously designed field tests, it is proved that the original accuracy is significantly improved from 0.3[Formula: see text]mm to 0.1[Formula: see text]mm, and the repeatability is obviously improved as well. The method proposed in this study can also be extended to similar systems, improving system accuracy and simplifying the calibration procedures.