Research On Error Correction Of Airborne Lidar Dat

The lidar attitude change caused by the vibration of uav platform is one of the important factors affecting the measurement accuracy of airborne lidar system.In order to obtain high precision airborne lidar point cloud data,a method of point cloud error correction under vibration of airborne platform is proposed in this paper.The vibration error of airborne lidar is corrected,which provides data support for the construction of high-precision digital elevation map,and has important reference value for the application of airborne lidar in surveying and mapping field.The main research contents of this paper are as follows:(1)Aiming at the problem of insufficient research on airborne lidar vibration error,this paper studies the vibration mechanism of uav platform and the error mechanism of airborne lidar under platform vibration: Based on the flight principle of multi-rotor UAV and the vibration test results of uav platform,the vibration source and vibration state of multirotor UAV are analyzed.Based on the principle of airborne lidar measurement and the vibration state of uav platform,the vibration error model of airborne lidar was constructed,and the vibration signal of UAV platform was used as the input of point cloud error model to simulate.The simulation results show that the influence of uav platform vibration on point cloud data accuracy is reflected in distortion error and inter-frame error of point cloud caused by single frame.(2)Aiming at the problems of point cloud image distortion and stratification caused by uav platform vibration,a point cloud distortion compensation method based on vibration data was proposed: Preprocess the original point cloud data output by lidar.Estimated the position of laser radar under the vibration of the drone platform via the IMU data and the vibration acceleration data.The attitude information of airborne lidar is combined with the vibration error model of airborne lidar to compensate point cloud distortion.The subsequent test results show that the proposed compensation method meets the design requirements and can effectively compensate the point cloud distortion errors caused by uav platform vibration.(3)Aiming at the problem of inter-frame error correction of airborne Lidar,based on the existing Lidar Odometry and Mapping(LOAM)algorithm,echo intensity information is introduced for point cloud registration: The input point cloud data is segmented and a frame of point cloud data is divided into multiple copies for registration.Feature extraction and feature matching were carried out on the input point cloud,and the intensity information of echo data was introduced in the feature extraction step,and the reflectance feature of the scan point was constructed based on the echo intensity and measured distance,and the reflectance feature was used as the edge feature to participate in feature matching.Smooth the point cloud after registration.The subsequent test results show that the proposed algorithm has a good effect on the correction of inter-frame error,and is also improved compared with the LOAM algorithm.