隧道三维激光扫描点云断面收敛参数相关性研究

基于移动三维激光扫描隧道点云数据,通过点云预处理、断面提取过滤,最后进行隧道管环实测轴径提取、椭圆拟合得到断面的水平轴径值、椭圆度等数值成果表及椭圆拟合等成果图。从几何形态学的角度,对横径与设计偏差、椭圆周长、椭圆均轴差等椭圆拟合结果参数与椭圆度之间数学关系及相关性进行统计分析与研究,探究隧道管环实测点云经过椭圆拟合出的长短轴长异常值的自动筛选方法。结果表明:椭圆度与横径值具有较强的线性相关性;椭圆均轴差D(椭圆长轴加短轴与两倍理论圆直径之差)与椭圆周长和理论圆周长之差d约束关系式,可以用作管环变形椭圆拟合长短轴长异常值的筛选依据。

Correlation Study on Convergence Parameters of Point Cloud Cross-section in Three-Dimensional Laser Scanning Tunnel

Based on the tunnel point cloud data obtained by the mobile three-dimensional (3D) laser scanning technology, point cloud preprocessing, section extraction and noisy point filtering were conducted, and the extraction of measured tunnel ring axial diameter and ellipse fitting were performed to obtain the numerical and graphic results of horizontal axial diameter, ovality, and other ellipse fitting results. From the perspective of geometric morphology, the mathematical relationship and correlation between ovality and ellipse fitting result parameters, such as the horizontal transverse diameter and design deviation, ellipse circumference, mean differences of ellipsoidal axis, were statistically analyzed and studied, while the automatic filtering method of long- and short-axis length outliers obtained by ellipsoidal fitting of measured point clouds of tunnel rings was explored. The results show a strong linear correlation between ovality and horizontal transverse diameter. The mean difference of the ellipsoidal axis D (the difference between the sum of the major and the minor axis of the ellipse and the doubled diameter of the theoretical circle) and the difference between the circumference of the ellipse and the theoretical circumference d obeys the constraint relation. This relation can be used as the filtering basis for the long- and short-axis length outliers in the ellipsoidal fitting of tunnel ring deformation.