基于动态模板的钢轨磨耗测量方法研究

Rail Wear Measuring Method Based on Dynamic Template

对CCD摄像机拍摄的钢轨表面轮廓测量光带进行图像处理,获得单个像素宽的二值化钢轨横截面轮廓;将结构光平面方程与摄像机投影矩阵相结合,对钢轨横截面轮廓进行三维重建,提取钢轨轮廓线中轨腰圆弧段圆心和轨头下端点2个特征点的世界坐标值;由2个特征点和钢轨上任意不与这两点共线的点以及标准钢轨横截面轮廓的空间几何关系动态生成标准模板;将钢轨实测轮廓和动态生成的标准模板轮廓的坐标映射到测量坐标系下,对比计算获得钢轨磨耗值。实验室验证结果表明:该方法能快速、准确地动态生成钢轨横截面轮廓模板,实现钢轨磨耗的高精度测量,且测量结果具有良好的重复性和稳定性。

The rail profile image with a measuring light band captured by CCD（Charge-coupled Device） camera is processed to obtain a binary image with a single pixel contour line of rail cross section.3-D reconstruction of the rail contour is realized by unifying the light planar function and the projection matrix of the camera.And the world coordinate values of the two feature points,which are arc center point of rail waist and lowest point of rail head,are extracted.The dynamic standard template of rail contour is generated based on three non-collinear points,which are the two feature points and another arbitrary point on rail profile,in combination with the spatial geometric relationship of the standard rail profile.A measuring coordinate is established.Then the dynamic standard template of rail contour and the measuring one are mapped into the measuring coordinate.Further comparative calculation is executed to get rail wear values.The laboratory experiment results show that this method is capable of fast generating dynamic standard template of rail contour with high accuracy,and of obtaining more precise wear values with well reliability and repeatability.