基于极坐标等角度分布的钢轨廓形测量误差校准
Rail profile measurement error calibration based on equal angle distribution method in polar coordinate system

摘要 针对钢轨廓形(轨廓)动态测量系统现场长期应用精度下降问题，提出采用接触式轨廓测量仪对动态测量系统进行校准.首先根据极坐标系等角度分布原则，分别对接触式测量轨廓和非接触式测量轨廓进行数字化建模和重采样处理.然后选取接触式测量轨廓作为基准，建立非接触式测量轨廓与基准轨廓之间的映射关系.最后通过对比二者偏差，实现轨廓动态测量系统误差现场校准.实际应用表明，经校准后的轨廓动态测量系统，静态测量误差由0.96 mm降低到0.14 mm，动态重复性误差最大值、平均值和均方根值分别为0.29 mm、0.13 mm和0.18 mm，验证了校准方法的可行性.
Abstract：In order to solve the long term onsite problem of accuracy decrease of the rail profile dynamic measurement system, the contact-type profile measurement instrument is proposed to correct the error of the dynamic measurement system. Firstly, the rail profiles, measured through the contact-type and noncontact-type methods, are digitized and resampled according to the principle of equal angle distribution in polar coordinate frame. Then, the contact-type rail profile is set as reference and the mapping relation between the contact-type and noncontact-type profiles can be established. Afterwards, the contact-type profile is compared with the noncontact-type profile based on the proposed method. The deviation, which is used for the error calibration, can be easily obtained. The onsite static experimental results show that the error of the corrected profile can be decreased from 0.96 mm to 0.14 mm. The onsite dynamic results indicate that the maximum value, mean value and root mean square value of the absolute error are within 0.29 mm, 0.13 mm and 0.18 mm, respectively. Both the onsite static and dynamic measurements demonstrate the effectiveness of the proposed method.