基于三维激光扫描的既有铁路中线勘测方法研究

线路勘测是既有铁路改造、维护以及与增建二线的重要环节,为解决铁路轨道三维激光点云不完整对钢轨线型提取的精度和影响等问题,提出一种基于钢轨结构特征约束匹配的三维激光点云轨道中心线自动提取新方法,通过将三维激光扫描获取的钢轨断面与标准钢轨相匹配,以标准钢轨中心线对遮挡和缺失的实际扫描钢轨中心线进行表达,从而精确计算钢轨中线三维坐标。对典型铁路场景不同激光扫描密度的3个点云数据集,采用新方法进行铁路中线测量实验,结果表明:在所有数据集中,高程中误差均小于4 mm,水平中误差均小于4 mm。因此,在复杂的铁路场景、三维激光点云被遮挡或缺失的情况下,新方法均能稳健计算铁路中心线,在既有线高精度勘测中具有广泛应用前景。

Research on Survey Method of Existing Railway Center Line Based on 3D Laser Scanning

Railway survey is an important link in the reconstruction,maintenance of existing railway and construction of its second line.In order to solve problems of incomplete 3D laser point cloud of railway track in terms of the accuracy and influence of rail line type extraction,a new method for the automatic extraction of railway center lines based on the constraint matching of rail structure characteristics is proposed.By matching the rail section obtained by the 3D laser scanning with the standard rail,the occluded and missing actual scanned rail center line is expressed by the standard rail centerline to accurately calculate it in threedimensional coordinates.With three points cloud data sets with different laser scanning densities in typical railway scenes,the new method was used to carry out railway centerline survey experiments.The results show that in all data sets,both the error in elevation and in level are less than 4mm.Therefore,the new method can reliably calculate the railway centerline in the case of complex railway scenes where the 3D laser point cloud is blocked or missed,and has broad application prospects in the high-precision surveys of existing railway lines.