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Poincloud Mapping

LIO-SAM-6AXIS

lio-sam-6axis

step-1: Install Docker

install docker

step-2: Install Nvidia Docker

install nvidia docker

step-3: build docker image

  • Clone the repository (repository map needs to be modified)
git clone https://github.com/pixmoving-moveit/LIO_SAM_6AXIS.git # clone repository
cd lio_sam_6axis # enter the repository folder
  • Build Docker image using Dockerfile in the repository
sudo docker build - < Dockerfile -t lidar_mapping

step-4: Run the Image

docker run -it --net=host --gpus all --name lidar_mapping -v $HOME/shared_dir:/home/lidar_mapping/data lidar_mapping /bin/zsh

If you need multiple terminal windows for operation, you can enter the container through the following command

docker exec -it lidar_mapping /bin/zsh

step-5: Build Mapping Workspace

Create a workspace

mkdir mapping_ws
cd mapping_ws
mkdir src
cd src
git clone https://github.com/pixmoving-moveit/LIO_SAM_6AXIS.git
cd ..

Compile the package

cd ~/mapping_ws
catkin_map

step-6: Sensor Calibration

Before mapping, you need to prepare the intrinsic parameters of your IMU and the extrinsic parameters of LiDAR and IMU.

step-7: Modifying configuration files

launch file

<launch>
    <arg name="project" default="lio_sam_6axis"/>
    <arg name="bag_path" default="/media/xchu/e81eaf80-d92c-413a-a503-1c9b35b19963/home/xchu/data/hkust/outdoors/hkust_20201105full.bag"/>
    <arg name="sequence" default="hkust_campus"/>

    <!--set your own Parameters -->
    <!--    <rosparam file="$(find lio_sam_6axis)/config/params_ouster.yaml" command="load"/>-->
    <rosparam file="$(find lio_sam_6axis)/config/params_vlp.yaml" command="load"/>

    <!--- LOAM -->
    <param name="saveDirectory" type="string" value="$(find lio_sam_6axis)/data/"/>
    <param name="configDirectory" type="string" value="$(find lio_sam_6axis)/config/"/>
    <rosparam param="sequence" subst_value="true">$(arg sequence)</rosparam>
    <include file="$(find lio_sam_6axis)/launch/include/module_loam.launch"/>

    <!--- Robot State TF -->
    <include file="$(find lio_sam_6axis)/launch/include/module_robot_state_publisher.launch"/>

    <!--show satellite-->
    <!--set your orgin gps lla  22.3387279108228 114.263622199692 87.7310562180355 -->
    <node pkg="rostopic" type="rostopic" name="fake_gps_fix"
          args="pub gps/fix sensor_msgs/NavSatFix '{ header: auto, latitude: 22.3387279108228, longitude: 114.263622199692, altitude:  87.7310562}'"
          output="screen"/>

    <!--- Run Navsat -->
    <node pkg="lio_sam_6axis" type="lio_sam_6axis_gpsOdometry" name="lio_sam_6axis_gpsOdometry" output="log"/>

    <!--- Run Rviz-->
    <node pkg="rviz" type="rviz" name="$(arg project)_rviz"
          args="-d $(find lio_sam_6axis)/launch/include/config/vlp.rviz"/>

    <node pkg="rosbag" type="play" name="bag_play" args="$(arg bag_path) --clock -d 5 -r 2.0"/>

</launch>

You need to modify the corresponding parameter file according to the launch file. Taking the above launch file as an example, the parameter file used is $(find lio_sam_6axis)/config/params_vlp.yaml, so the relevant parameters should be modified in this file.

  • The msg configuration for your sensor needs to be modified. lio-sam-topic
Parameter Msg Type Description
pointCloudTopic sensor_msgs/Pointcloud2 Topic for LiDAR point cloud
imuTopic sensor_msgs/Imu Topic for IMU
odomTopic nav_msgs/Odometry Topic for IMU Odometry, no need to modify
gpsTopic nav_msgs/NavSatFix Topic for GNSS localization

  • If using GNSS, set useGPS to true and set the correct GPS frequency in gpsFrequence gps-params

  • LiDAR parameters lidar-params

Parameter Description
sensor Type of LiDAR, options: velodyne, ouster, livox, hesai
N_SCAN Number of channels of pointcloud, 16 for 16-beam LiDAR
Horizon_SCAN Horizontal resolution of LiDAR (Velodyne:1800, Ouster:512,1024,2048, Livox Horizon: 4000)
downsampleRate Downsampling rate, such that N_SCAN/downsampleRate=16
lidarMinRange Minimum range of point cloud, default is 1.5
lidarMaxRange Maximum range of point cloud, default is 1000.0
Parameter Description
imuAccNoise Mean of 3-axis accelerometer white noise (m/s^2)
imuGyrNoise Mean of 3-axis gyroscope white noise (rad/s)
imuAccBiasN Mean of 3-axis accelerometer bias (m/s^2)
imuGyrBiasN Mean of 3-axis gyroscope bias (rad/s)
imuGravity Local gravity acceleration (m/s^2)
imuRPYWeight Euler angle weight, default is 0.01
Parameter Description
imu_type Type of IMU (0: 6-axis, 1: 9-axis)
extrinsicTrans Translation matrix
extrinsicRot Rotation matrix

step-8: Run mapping program

Run mapping launch file

roslaunch lio_sam_6axis run.launch

Play rosbag

rosbag play -r 3.0 [path of bag file]

step-9: Save map

rosservice call /lio_sam_6axis/save_map

After saving the map, the following files can be found in the map folder:

name 描述
global_map_lidar.pcd Pointcloud map, already converted to ENU direction if using GNSS
origin.txt Latitude, longitude, and altitude of the origin of pointcloud map

References