l3cam_fusion

This is a ROS2 package for the visualization of the fusion of the L3Cam device sensors. This package relies on Beamagine's matrix files. It is intended to be used with the l3cam_ros2 package topics.

This package has only been tested with ROS2 foxy on an Ubuntu 20.04 system.

Installation

Clone this repository in your ROS2 workspace (e.g. ros2_ws) and build:

cd ~/ros2_ws/src && git clone https://github.com/beamaginelidar/l3cam_fusion
colcon build --packages-select l3cam_fusion

Nodes

fusion_lidar_img

The fusion_lidar_img node fuses the LiDAR sensor with an image sensor (such as RGB or IR) in real time by projecting the points of the LiDAR point cloud to the image sensor.

The node first gets the fusion matrix from the matrix file, then gets the projection for each arriving point cloud, paints the projection on the image with the nearest timestamp to the point cloud timestamp, and publishes each image with the projection.

The name of the topic at which the fusion data gets published is fusion by default, but it can be named as desired by changing the fusion_topic parameter. This is because it is possible to show the fusion for different sensors by launching the same node with different parameters regarding different sensors of the same L3Cam.

To run this node you must first set the node parameters. You can set the parameters and run the node in different ways:

• By editing the fusion_lidar_img_launch.xml file arguments and launching it:

ros2 launch l3cam_fusion fusion_lidar_img_launch.xml

• By launching the fusion_lidar_img_launch.xml and passing the arguments via command line:

ros2 launch l3cam_fusion fusion_lidar_img_launch.xml "<PARAMETER_1>:=<VALUE_1>" "<PARAMETER_2>:=<VALUE_2>" ... "<PARAMETER_N>:=<VALUE_N>"

• By editing the fusion_lidar_img.yaml file and running the node:

ros2 run l3cam_fusion fusion_lidar_img --ros-args --params-file src/l3cam_fusion/fusion_lidar_img.yaml

Parameters

fusion_lidar_img parameters

Parameter	Type	Description
mat_file	string	Route to the matrix file.
sensor_name	string	Name of the image sensor. Check the sensor names in the matrix file.
print_matrix	bool	Bool to choose if you want to see the fusion matrix printed in the terminal.
lidar_topic	string	The name of the topic to subscribe from where to get the point clouds.
img_topic	string	The name of the topic to subscribe from where to get the images.
fusion_topic	string	The name of the topic to publish the fusion.
pointcloud_color	int	Point cloud color visualization type. See the visualization options.
color_value_min	int	The minimum value of distance (in mm) at which Rainbow colors repeat and of values at which Intensity color shows, depending on the pointcloud_color value.
color_value_max	int	The maximum value of distance (in mm) at which Rainbow colors repeat and of values at which Intensity color shows, depending on the pointcloud_color value.
projection_points_radius	int	Radius (in pixels) of the points projected

Real time changeable parameters

The following parameters can be changed while the node is running in real time:

Parameter	Type	Default	Range
pointcloud_color	int	3	[0, 4]
color_value_min	int	0	[0, 200000]
color_value_max	int	10000	[0, 200000]
projection_points_radius	int	3	[0, 15]

They can be changed with dynamic reconfigure or with command line:

ros2 param set /fusion_lidar_img <PARAMETER> <VALUE>

pointcloud_color options

(See visualizationTypes)

• WHITE = 0
• INTENSITY = 1
• RGB = 2
• RAINBOW = 3
• RAINBOW_Z = 4