Point Clouds Registration Of Terrestrial Three-dimensional Laser Scanner

The object of this thesis is the registration technology on point clouds of terrestrial laser scanner.The registration of point clouds acquired from different stations is the key step in Terrestrial Laser Scanner data processing.It not only determines the workflow of scanning measurement,but also is one of the most important factors in the accuracy of data preprocessing and modeling.The topic of this thesis is to study different ways of point clouds registration technologies in order to improve point clouds registration speed and accuracy.The specific work is as follows:1.This thesis researches on improvement of the ICP algorithm for registration of two station point clouds based on rigid constraint consistency.For the multi-view point clouds with rough registration,this paper presents the point coordinates constraint to remove the wrong corresponding points.The experiment result shows that the algorithm improves the iteration speed and registration efficiency without adding the complexity of calculating.2.For the multi-view point clouds without rough registration,this paper designs the adaptive threshold method to remove the wrong corresponding points by calculating the distance-mean square error of the corresponding points and setting threshold,the experiment result shows that the new algorithm obviously reduces iteration time and improves registration efficiency without adding the complexity of calculating.3.For the scanners with leveling and compensation functions,this paper proposes a registration method based on a single plane point clouds that different stations both have.First we extract the shared-plane feature from the scanning scene,then do plane fitting,remove noise,calculate plane normal vector accurately,carry out the rotation matrix using normal vector and centre point,at last,complete registration.This paper conduct an experiment using simulated and measured data to verify the feasibility of the proposed method.4.For the scanners without leveling and compensation functions,the thesis proposed another registration method of point clouds based on double plane,the calculate steps and simulation example are given,the feasibility of the algorithm is verified.5.By analyzing the different common point coordinate conversion method,this paper proposes a method for multi-station registration based on the Rodrigo Matrix with Total Least Square.It gives the solution to verify the accuracy of the registration with simulated data.Through experiments with simulated and measured data to verify the proposed algorithm,the results show that the proposed method improves the registration precision.6.By studying the 6dof three-dimensional net adjustment,this thesis derivates the multi-station registration formulas based on public target points.Through experiments with simulated and measured data to verify the proposed algorithm and the results show that the proposed method improves the registration precision.