基于激光扫描点云的隧道断面提取方法

传统断面测量方法存在效率低、精度差等特点,为优化断面测量方法,提出利用地面激光点云提取断面的方法。其主要包括:中轴线拟合、点云分割、断面提取三步骤。在基于点云双向投影确定初始中轴线的基础上,运用弦高偏移算法,提取骨架特征拐点,对中轴线分段再次拟合,获取二次中轴线;点云分割是基于隧道中轴线进行的,对隧道的点云数据进行连续分割,对截取的断面进行椭圆拟合。实验表明,通过此方法快速提取中轴线上任意位置的断面。

Application of laser scanning point clouds to the subway tunnel section extraction

The traditional cross-section measurement method has the shortcomings of low efficiency and poor precision.In order to optimize the method of cross-section measurement, this paper proposes to use ground laser point cloud to extract section.It mainly includes three main steps: center axis fitting, point cloud segmentation and section extraction.On the basis of determining initial axial line based on the bi-directional projection of point cloud, the chord height offset algorithm is used to extract the inflection point of framework feature, and the central axis segment is re-fitted to obtain secondary central axis;the point cloud segmentation is implemented based on tunnel central axis, point cloud data of the tunnel is segmented continuously, and the intercepted sections are elliptically fitted.Experiments show that this method can be used to quickly extract the cross section of any position on the central axis.