三维激光扫描技术为大型交通工程的全三维表面量测提供了一种有效的技术手段。但是面对扫描输出的海量原始点云数据，如何从中快速、精确地提取工程几何信息就变成一个亟待解决的问题。文中设计了一种从三维点云中自动提取隧道几何特征线的方法，仅以带有三维坐标的点云数据输入，不需提供额外的隧道相关参数，根据隧道表面法向与隧道中轴走向、隧道断面之间的几何关系，自动跟踪中轴线并确定截面方向，截取断面轮廓线。适用于弯曲型隧道，能够根据隧道走向精确调整中轴线方向和截面法向，在实际工程应用中具有较强的实用性。%T he 3D laser scanning technology provides an effective method for measuring complete surface of the large‐scale traffic engineering .In practice ,to quickly extract the accurate geometric features from massive point cloud becomes an urgent problem to be solved .This paper describes an automatic extraction schema for the linear features of tunnel ,such as central axis and cross‐sectional contours , w hich can correctly identify the trend of tunnel and determine the normal direction of cross section based on the lots of neighboring points with normal vector .In addition ,it is a specially designed readjustment strategy for refining the sectional direction that makes this schema also applicable to curved tunnels .With the real tunnel‐scanning data ,the final experimental results demonstrate this method can be practical in the engineering and practicably .
展开▼
