Lightweight 3-D Localization and Mapping for Solid-State LiDAR (Intel Realsense L515 as an example) ported to ROS2 Humble
This repo is an extension work of SSL_SLAM. Similar to RTABMAP, SSL_SLAM2 separates the mapping module and localization module. Map saving and map optimization is enabled in the mapping unit. Map loading and localization is enabled in the localziation unit.
This code is an implementation of paper "Lightweight 3-D Localization and Mapping for Solid-State LiDAR", published in IEEE Robotics and Automation Letters, 2021 paper
A summary video demo can be found at Video
Modifier: Wang Han, Nanyang Technological University, Singapore
Running speed: 20 Hz on Intel NUC, 30 Hz on PC
Ubuntu 64-bit 22.04.
ROS Humble. ROS Installation
sudo apt install libceres2 libceres-dev
Follow PCL Installation.
Tested with 1.8.1
sudo add-apt-repository ppa:borglab/gtsam-release-4.1
sudo apt update
sudo apt install libgtsam-dev libgtsam-unstable-dev
For visualization purpose, this package uses hector trajectory sever, you may install the package by
sudo apt-get install ros-melodic-hector-trajectory-server
Alternatively, you may remove the hector trajectory server node if trajectory visualization is not needed
If you have new Realsense L515 sensor, you may follow the below setup instructions
Follow Librealsense Installation
Copy realsense_ros package to your catkin folder
cd ~/catkin_ws/src
git clone https://github.com/IntelRealSense/realsense-ros.git
cd ..
catkin_make
cd ~/<your_ros2_ws>/src
git clone https://github.com/TiNredmc/ssl_slam2_ros2.git
cd ..
colcon build --symlink-install --packages-select ssl_slam2 --parallel-workers 4
source ~/<your_ros2_ws>/install/setup.bash
if you encounter c++: fatal error: Killed signal terminated program cc1plus you might need to rebuild again using
colcon build --symlink-install --packages-select ssl_slam2 --executor sequential
or
MAKEFLAGS="-j3 -l1" colcon build --symlink-install --packages-select ssl_slam2 --executor sequential
You may download our recorded data: MappingTest.bag (3G) and LocalizationTest.bag (6G)if you dont have realsense L515, and by defult the file should be under home/user/Downloads
unzip the file (it may take a while to unzip)
cd ~/Downloads
unzip LocalizationTest.zip
unzip MappingTest.zip
map optimization and building
ros2 launch ssl_slam2 ssl_slam2_mapping.launch.py
The map optimization is performed based on loop closure, you have to specify the loop clousre manually in order to trigger global optimization. To save map, open a new terminal and
ros2 service call /save_map std_srvs/srv/Trigger
Upon calling the serviece, the map will be automatically saved. It is recommended to have a loop closure to reduce the drifts. Once the service is called, loop closure will be checked. For example, in the rosbag provided, the loop closure appears at frame 1060-1120, thus, when you see "total_frame 1070" or "total_frame 1110" you may immediately type
ros2 service call /save_map std_srvs/srv/Trigger
Since the current frame is between 1060 and 1120, the loop closure will be triggered automatically and the global map will be optimized and saved
Type
roslaunch ssl_slam2 ssl_slam2_localization.launch
If your map is large, it may takes a while to load
The map size depends on number of keyframes used. The more keyframes used for map buildin, the larger map will be.
min_map_update_distance: distance threshold to add a keyframe. higher means lower update rate. min_map_update_angle: angle threshold to add a keyframe. higher means lower update rate. min_map_update_frame: time threshold to add a keyframe. higher means lower update rate.
The relocalization module under tracking loss is still under development. You must specify the robot init pose w.r.t. the map coordinate if the starting position is not the origin of map. You can set this by
<param name="offset_x" type="double" value="0.0" />
<param name="offset_y" type="double" value="0.0" />
<param name="offset_yaw" type="double" value="0.0" />
The realsense is running at 30Hz and some computer may not be able to support such high processing rate. You may reduce the processing rate by skipping frames. You can do thid by setting the
<param name="skip_frames" type="int" value="1" />
1 implies no skip frames, i.e., 30Hz; implies skip 1 frames, i.e., 15Hz. For small map building, you can do it online. however, it is recommended to record a rosbag and build map offline for large mapping since the dense map cannot be generated in real-time.
You may download a larger dataset LargeMappingTest.bag (10G), and by defult the file should be under home/user/Downloads
unzip the file (it may take a while to unzip)
cd ~/Downloads
unzip LargeMappingTest.zip
Two loop closure places appear at frame 0-1260 and 1270-3630, i.e., frame 0 and frame 1260 are the same place, frame 1270 adn 3630 are the same place. Run
roslaunch ssl_slam2 ssl_slam2_large_mapping.launch
open a new terminal, when you see "total_frame 1260", immediately type
rosservice call /save_map
when you see "total_frame 3630", immediately type again
rosservice call /save_map
If you use this work for your research, you may want to cite the paper below, your citation will be appreciated
@article{wang2021lightweight,
author={H. {Wang} and C. {Wang} and L. {Xie}},
journal={IEEE Robotics and Automation Letters},
title={Lightweight 3-D Localization and Mapping for Solid-State LiDAR},
year={2021},
volume={6},
number={2},
pages={1801-1807},
doi={10.1109/LRA.2021.3060392}}