地面三维激光扫描多站点云数据配准新方法

Registration for multi-station point cloud of terrestrial laser scanning

针对点云数据两两配准中存在误差传递与累积的缺点,提出一种新的多视点云数据配准方法.该方法首先构建一个统一扫描网坐标系,即选取某一扫描坐标系作为统一的扫描网坐标系,利用两两配准计算出相邻两个点云数据间的变换参数,并计算出各站点云数据在统一扫描网坐标系下的坐标;结合相邻测站间的公共点,以首站点在统一扫描坐标系下的坐标经非线性变形改正后应与首站实际扫描坐标相等、相邻扫描站公共点经非线性变形改正后坐标应相等为条件,借助非线性变形改正模型计算出各个点云的非线性变形参数,从而实现对每站扫描点云数据进行改正,以降低误差传递带来的累积效应.实验表明,此方法能提高点云数据配准精度.

Pair-wise registration is a common method for registration of multi-views point clouds. Owing to the characteristics of error propagation and accumulation, using pair-wise registration method will result in severe distortion for object researched. In order to overcome this shortcoming, we present a new registration method. Firstly, we adopted coordinate sys- tem of first scan as a uniform coordinate system, used pair-wise registration method to calcu- late transformation parameters of adjacent two scans, and connected all point clouds into a loose network. Secondly, based on the common points that point cloud is adjacent to, and con- ditions that the first scan must have the same coordinates with real scanning coordinates in the first scan coordinate system, and common points between adjacent point clouds should haves the same coordinates in uniform system, we used nonlinear correction model to compute distor- tion parameters of each point cloud. And lastly we corrected distortion of each single point clouds and determined their best positions. An experiment was carried out and the result showed the correctness of the method.