针对椭圆形隧道底部的横断面分割及滤波  

Cross-section segmentation and filtering for the bottom of elliptical tunnel

作　　者：牛晓洁 季民[1] 徐飞 NIU Xiaojie;JI Min;XU Fei(College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao Shandong 266590, China;Fuzhou Investigation and Surveying Institute Company Limited, Fuzhou Fujian, 350000, China)

机构地区：[1]山东科技大学测绘与空间信息学院,山东青岛266590 [2]福州市勘测院,福建福州350000

出　　处：《北京测绘》2022年第3期321-328,共8页Beijing Surveying and Mapping

基　　金：山东省重大科技创新工程项目(2019JZZY020103)。

摘　　要：针对基于三维激光点云的底部为矩形的椭圆形隧道横断面提取及拟合问题,本文提出一种对该类隧道进行隧道中线提取、横断面提取、分割及拟合的方法。该方法首先根据隧道腰部连接处的边界点云特征提取出腰部边界线并求取出腰部中线,接着使用腰部中线建立横断面方程并切割出隧道点云切片,然后使用随机抽样一致算法(random sample consensus,RANSAC)结合平面法向量约束模型对隧道底部点云进行滤波分离,从而实现隧道横断面的圆形部分与矩形部分的分割,最后对圆形部分进行拟合并滤波,通过实验表明本文方法能够准确较高精度的腰部中线及横断面,能够对将横断面的底部进行较好地分割并拟合圆形部分,能够为相关工作应用及科研工作提供技术支持。Aiming at the problem of extracting and fitting the cross section of an elliptical tunnel whose bottom is a rectangle based on a three-dimensional laser point cloud,this paper proposed a method of tunnel centerline extraction,cross section extraction,segmentation and fitting for this type of tunnel.This method firstly extracted the waist boundary line and obtains the waist midline according to the boundary point cloud features at the waist junction of the tunnel,then used the waist midline to establish the cross-sectional equation and cuts out the tunnel point cloud slices,and then used the RANSAC algorithm combined with the plane normal vector to constrain the model.The point cloud at the bottom of the tunnel was filtered and separated,so as to realize the segmentation of the circular part and the rectangular part of the tunnel cross section.Finally,the circular part was fitted and filtered.Experiments showed that the method in this paper could accurately and accurately determined the waist midline and cross section.It is better to segment the bottom of the cross section and fit the circular part,and can provide technical support for related work applications and scientific research.

关 键 词：三维激光点云 隧道横断面 平面法向量 分割及拟合 

分 类 号：P258[天文地球—测绘科学与技术]