基于盾构隧道环缝点云的中轴线提取方法

为了降低盾构隧道中轴线提取对原始点云预处理的要求,引入了点云特征提取方法。 首先, 以基于距离差特征的裂缝点云提取方法,识别盾构隧道管片拼接处的环缝点云;然后,以最小二乘 法对提取的环缝内散点进行环缝曲线拟合;最后,在环缝曲线的基础上提取隧道中轴线。 实验结果 表明:基于距离差特征的点云提取方法能够有效识别环缝点云,并在环缝点云的基础上拟合得到隧 道中轴线。 与传统提取方法相比,该方法更加快捷,且提取的中轴线更具有空间感。

Central axis extraction method of shield tunnel based on ring seam point cloud

In order to reduce the requirement of original point cloud preparation for the axis extraction of shield tunnel, a feature extraction method of point cloud is introduced in this study. Firstly, the ring joint point cloud of shield tunnel segment was identified based on the extraction method of crack point cloud with the distance difference feature. Then, the curve fitting of the interstitial points was carried out by the least square method. At last, the central axis of the tunnel is extracted on the basis of the circular seam curve. Experimental results show that the point cloud extraction method based on the distance difference feature can effectively identify the ring seam point cloud, and fit the tunnel central axis on the basis of the ring seam point cloud. Compared with the traditional extraction method, the proposed method is faster, and the extracted central axis is more spatial.