摘要
近年来,三维激光扫描技术广泛运用于公路隧道的几何参数测量。针对高速公路隧道的三维激光扫描点云,设计了一种从中提取完整断面轮廓线的自动化方法。该方法能够自动结合大量点的法向信息精确计算出隧道中轴线,并以此建立与隧道同轴的参考圆柱面;然后利用专门设计的圆柱投影方法将点云映射至二维空间,并改进了二维Delaunay构网算法使之适用于周期性圆周角数据的构网问题;最后基于隧道表面三角网自动截取断面轮廓。另外,该方法能够根据隧道走向的变化自动调整截面方向,可应用于弯曲隧道工程,并以真实的高速公路隧道扫描数据验证了算法的有效性和高效性。
In recent years,3D laser scanning technology has been applied to measure the geometrical parameters of highway tunnels. For the 3D laser scanning point clouds of an highway tunnel,a method of automatically extracting complete contours of cross-sections from the point coulds was proposed. This method can accurately compute the central axis of the tunnel by taking advantage of abundant normal vectors embedded in point clouds,and then build a reference cylinder surface coaxial with the tunnel. Moreover,a cylndrical projection for mapping all point clouds into a 2D space was designed,and an improved algorithm of the classic Delaunay triangulation was put forward to resolve the triangulation problem of the border-less circumferential angles. Finally,by intersecting 3D triangular mesh of tunnel with the cross sections,a series of contours were generated at the specified locations. In addition,for the curved tunnels,this method can adjust the direction of sections automatically to make them suitable for the constantly changing direction of the tunnel. The effectiveness and high efficiency of this method was verified by the actual scanning data of a highway tunnel.
出处
《水利与建筑工程学报》
2015年第2期47-52,共6页
Journal of Water Resources and Architectural Engineering
关键词
三维点云
弯曲隧道
圆柱投影
Delaunay构网
3D laser scanning point clouds
curved tunnel
cylndrical projection
Delaunay triangulation
