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Function Introduction

LDLIDAR ROS2 driver sends laser radar data in ROS2 standard message format.

Item List

For detailed product models, please refer to LDLIDAR official website using LDLIDAR X3 as an example.

Item Option	Inventory
RDK X3	Purchase Link
LDLIDAR X3	Purchase Link

Usage

Preparation

1. The Horizon RDK has been flashed with the Ubuntu 20.04 system image provided by Horizon.

2. LDLIDAR correctly connected to RDK X3.

Installing the LDLIDAR Driver

Connect to RDK X3 via terminal or VNC, and execute the following commands:

tros foxy:

sudo apt update
sudo apt install -y tros-ldlidar_ros2

tros humble:

sudo apt update
sudo apt install -y tros-humble-ldlidar_ros2

Note: If LDLIDAR is connected to RDK X3 during installation, it needs to be plugged in again after installation.

Running LDLIDAR

tros foxy:

source /opt/tros/setup.bash
ros2 launch ldlidar_ros2 ld06.launch.py

tros humble:

source /opt/tros/humble/setup.bash
ros2 launch ldlidar_ros2 ld06.launch.py

Viewing Radar Data

Method 1: Command Line

Open a new terminal and enter the following command to view laser radar output data:

tros foxy:

source /opt/tros/setup.bash
ros2 topic echo /scan

tros humble:

source /opt/tros/humble/setup.bash
ros2 topic echo /scan

Method 2: Using Foxglove Visualization

Note: The device running Foxglove Studio should be on the same network segment as the RDK device.

1. Go to the Foxglove official website to download Foxglove Studio and install it on your PC.

2. Open a new terminal on RDK and enter the following command to install rosbridge:

   tros foxy:

   sudo apt update
   sudo apt install ros-foxy-rosbridge-suite

   tros humble:

   sudo apt update
   sudo apt install ros-humble-rosbridge-suite

3. Run the following command to start rosbridge:

   tros foxy:

   source /opt/tros/setup.bash
   ros2 launch rosbridge_server rosbridge_websocket_launch.xml

   tros humble:

   source /opt/tros/humble/setup.bash
   ros2 launch rosbridge_server rosbridge_websocket_launch.xml

4. Open Foxglove Studio, select "Open Connection," choose rosbridge as the connection method in the subsequent dialog, and enter the RDK's IP address instead of localhost.

5.In Foxglove Studio, click the "Settings" button in the upper right corner, and in the panel that pops up on the left, configure the radar topic to be "visible." At this point, the studio will display the radar point cloud in real-time.

Method 3: RVIZ

Install ROS2 on a PC or an environment that supports RVIZ. Here, we take the foxy version as an example, run:

tros foxy:

source /opt/ros/foxy/setup.bash
ros2 run rviz2 rviz2

tros humble:

source /opt/ros/humble/setup.bash
ros2 run rviz2 rviz2

Add LaserScan and configure the Reliability Policy as System Default.

Set Fixed Frame to base_link or laser_link to see the laser radar collected data.

Interface Specification

Topic

Published Topic

Topic	Type	Description
scan	sensor_msgs/LaserScan	Two-dimensional laser radar scan data
pointcloud2d	sensor_msgs/PointCloud	Two-dimensional laser radar 2D point cloud data

Parameters

Parameter name	Data Type	Detail
frame_id	string	Default value for frame name: laser_frame
product_name	string	Radar type names: LDLiDAR_LD14,M10_P,M10_PLUS,M10_GPS,N10,L10,N10_P
port_name	string	Set the port number of the laser radar device For example, serial port /dev/ttyUSB0
serial_baudrate	int	Serial port baud rate. Default value: 115200
enable_angle_crop_func	bool	Enable angle cropping function. Default value: False
angle_crop_min	float	Starting angle for cropping. Default value: 135.0
angle_crop_max	float	Ending angle for cropping. Default value: 225.0
range_min	float	Minimum distance received by radar. Default value: 0.02
range_max	float	Maximum distance received by radar. Default value: 8.0
scan_topic	string	Set the topic name for laser data: /scan
point_cloud_2d_topic_name	string	Set the topic name for laser data: /pointcloud2d