2d_lidar_undistortion

A ros package used to correct motion distortion of a 2D LIDAR.

Introduction

利用IMU数据对2D激光雷达数据进行运动畸变校正（仅限于旋转校正）。imu的更新频率高于100Hz时，效果更佳。

This ros package uses standard IMU message to correct motion distortion of a 2D LIDAR in real time(rotation only). It is better that the update frequency of IMU is higher than 100Hz.

Usage

订阅话题：sensor_msgs::LaserScan 以及 sensor_msgs::Imu

Subcribed topics: sensor_msgs::LaserScan and sensor_msgs::Imu

A rosbag for test 2d_undistortion_example_1.bag. The rosbag is recorded with RPLIDAR A1 and Xsens MTI-300. (百度云链接2d_undistortion_example_1.bag，提取码r00m）

How to test the rosbag?

1. Start ros master. roscore
2. Play the rosbag with sim time and X0.5 speed, and press spacebar to pause. rosbag play 2d_undistortion_example_1.bag --clock -r 0.5
3. Start lidar_undistortion node. roslaunch lidar_undistortion lidar_undistortion_offline.launch
4. Press spacebar in the rosbag terminal to continue playing data.
5. The results will be shown in rviz. Raw scan is displayed with red points and output is displayed with white points.

Parameters in launch file

参数名	类型	解释
lidar_topic	string	订阅的激光数据话题名
lidar_msg_delay_time	double	雷达数据传输滞后的估计，单位毫秒，一般在10ms内
scan_direction_clockwise	bool	激光雷达扫描旋转方向，true为顺时针，false为逆时针；方向不对会增大畸变
imu_topic	string	订阅的imu话题名
imu_frequency	double	估计的imu发布频率，仅用来确定队列长度，不需要很精确
output_frame_id	string	输出消息的frame_id
pub_raw_scan_pointcloud	bool	是否发布校正前的点云
pub_laserscan	bool	是否将校正后的数据重新封装为LaserScan消息发布
laserscan_angle_increment	double	接上条，发布的LaserScan消息的角度分辨率，分辨率越小，转换精度越高，单位为弧度（空白数据用nan填充）
use_range_filter	bool	是否限定输出的扫描距离
range_filter_min	double	扫描距离的最小值
range_filter_max	double	扫描距离的最大值
use_angle_filter	bool	是否限定输出的角度范围，默认为$-\pi$到$+\pi$
angle_filter_min	double	扫描角度的最小值，单位为弧度
angle_filter_max	double	扫描角度的最大值，单位为弧度
use_radius_outlier_filter	bool	是否使用PCL库的RadiusOutlierRemoval滤波器，用来移除离群点
radius_outlier_filter_search_radius	double	RadiusOutlierRemoval滤波器参数，搜索半径
radius_outlier_filter_min_neighbors	double	RadiusOutlierRemoval滤波器参数，有效点的最少近邻点数量