LD Lidar ROS 2 Package

ROS 2 package for LDRobot lidar - Based on Nav2 Lifecycle nodes

Get the Lidar • YouTube Videos • Install • Start the Node • Parameters • RViz2 • Robot Integration • Benchmarking

This package is designed to work with the DToF 2D Lidar sensors LD19 made by LDRobot.

It can work also with the LD06 model, but no tests have been performed with it. LD06 cannot work outdoor.

LD19	LD06

Get the lidar

My lidar (LD19) comes from the LDRobot kickstarter campaing ended in 2021.

LDRobot then created also an Indiegogo campaign for the LD19.

LDRobot today distributes the Lidar through third-party resellers:

• Waveshare: LD19
• Innomaker: LD06
• Other: Search on Google

The node in action

LD19 Lifecycle	LD19 outdoor

Install the node

The node is designed to work with

• ROS 2 Humble
• ROS 2 Jazzy

:pushpin: Note: ROS 2 Rolling is not yet supported because of the missing nav2_utils dependency

Clone the repository in your ROS2 workspace:

cd ~/ros2_ws/src/ #use your current ros2 workspace folder
git clone https://github.com/Myzhar/ldrobot-lidar-ros2.git

Add dependencies:

sudo apt install libudev-dev

Install the udev rules

cd ~/ros2_ws/src/ldrobot-lidar-ros2/scripts/
./create_udev_rules.sh

Build the packages:

cd ~/ros2_ws/
rosdep install --from-paths src --ignore-src -r -y
colcon build --symlink-install --cmake-args=-DCMAKE_BUILD_TYPE=Release

Update the environment variables:

echo source $(pwd)/install/local_setup.bash >> ~/.bashrc
source ~/.bashrc

Start the node

Launch file with YAML parameters

The default values of the parameters of the node can be modified by editing the file ldlidar.yaml.

Open a terminal console and enter the following command to start the node with customized parameters:

ros2 launch ldlidar_node ldlidar_bringup.launch.py

The ldlidar_bringup.launch.py starts a ROS 2 Container, which loads the LDLidar Component as a plugin.

The ldlidar_bringup.launch.py script also starts a robot_state_publisher node that provides the static TF transform of the LDLidar [ldlidar_base->ldlidar_link], and provides the ldlidar description in the /robot_description.

Lifecycle

The ldlidar node is based on the ROS2 lifecycle architecture, hence it starts in the UNCONFIGURED state. To configure the node, load all the parameters, establish a connection, and activate the scan publisher, the lifecycle services must be called in sequence.

Open a new terminal console and enter the following command:

ros2 lifecycle set /ldlidar_node configure

If the node is correctly configured and the connection is established, Transitioning successful is returned. If there are errors, Transitioning failed is returned. Check the node log for details on any connection issues.

The node is now in the INACTIVE state, enter the following command to activate:

ros2 lifecycle set /ldlidar_node activate

The node is now activated and the /ldlidar_node/scan topic of type sensor_msgs/msg/LaserScan is available to be subscribed.

File truncated at 100 lines see the full file

Submitting your code changes

Code contributions should be made via pull requests to the appropriate repository:

• ldrobot-lidar-ros2

As a contributor please follow the practices explained in ROS2 documentation.

Before submitting a pull request please perform this list of tasks from the root of your ROS2 workspace:

1. Automatic code formatting:

   $ ament_uncrustify --reformat src

2. Build the packages to check for compile errors:

   $ colcon build --symlink-install --cmake-args=-DCMAKE_BUILD_TYPE=Release

3. Perform the automatic build tests:

   $ colcon test

4. Analyze and solve eventually reported errors:

   $ colcon test-result --verbose

5. Repeat steps (1) -> (4) until all reported formatting errors have been resolved.

License

Any contribution that you make to this repository will be under the Apache 2 License, as dictated by that license:

5. Submission of Contributions. Unless You explicitly state otherwise,
   any Contribution intentionally submitted for inclusion in the Work
   by You to the Licensor shall be under the terms and conditions of
   this License, without any additional terms or conditions.
   Notwithstanding the above, nothing herein shall supersede or modify
   the terms of any separate license agreement you may have executed
   with Licensor regarding such Contributions.

Contributors must sign-off each commit by adding a Signed-off-by: ... line to commit messages to certify that they have the right to submit the code they are contributing to the project according to the Developer Certificate of Origin (DCO).