No calibration files required

[JianWangInno]

For Innovusion's LiDAR, data calibration is all done within the LiDAR itself, and no calibration is required on the client side. However, in the existing framework, the system cannot run properly without providing a calibration file. Can the launch script be modified to remove this restriction?

[amc-nu]

The project currently does not have decoders for Innovusion's Lidar. However, if implemented from scratch, it should be possible to create an Innovusion HW connection and Packet Decoder inheriting from NebulaHwInterfaceBase and NebulaDriverBase, respectively.

[JianWangInno]

The project currently does not have decoders for Innovusion's Lidar. However, if implemented from scratch, it should be possible to create an Innovusion HW connection and Packet Decoder inheriting from NebulaHwInterfaceBase and NebulaDriverBase, respectively.

Thank you for your reply. Currently, Lidar from innovusion has submitted a PR and will face this issue once merged.

[amc-nu]

Thank you for providing additional information, and thank you for your PR.
In this case, creating a new launch file might be better. Starting from ROS2 Humble, we recommend XML files.
The following link shows a tutorial on using composable nodes within XML launch files.
https://docs.ros.org/en/humble/How-To-Guides/Launching-composable-nodes.html

[JianWangInno]

Thank you for providing additional information, and thank you for your PR. In this case, creating a new launch file might be better. Starting from ROS2 Humble, we recommend XML files. The following link shows a tutorial on using composable nodes within XML launch files. https://docs.ros.org/en/humble/How-To-Guides/Launching-composable-nodes.html

Thank you for your solution. We will support it in the next version.

[JianWangInno]

Thank you for providing additional information, and thank you for your PR. In this case, creating a new launch file might be better. Starting from ROS2 Humble, we recommend XML files. The following link shows a tutorial on using composable nodes within XML launch files. https://docs.ros.org/en/humble/How-To-Guides/Launching-composable-nodes.html

In ROS2, XML Launch files do not support defining composite nodes in the same way as ComposableNode in Python. XML Launch files are primarily used for starting and configuring nodes and do not provide the same level of advanced programming capabilities as Python code.

When we use XML launch files to start Nebula, we found that the hw_interface, monitor, and decoder nodes are running in separate processes, which can lead to performance degradation. On the other hand, using Python launch files allows us to utilize the concept of composite nodes, where all three nodes run in the same process. Based on my research, XML launch files currently do not support composite nodes. To ensure efficiency, would it be possible for us to modify Nebula's nebula_launch.py? Alternatively, could we create a new file called nebula_launch_innovusion.py to address this issue with multiple processes?

[amc-nu]

You can create a component container and add the composable nodes. Please look at the link I shared above. It contains an example. Click on the XML tab.

https://docs.ros.org/en/humble/How-To-Guides/Launching-composable-nodes.html#launch-file-examples

[JianWangInno]

I have tried according to the document you provided, but unfortunately, the error message is as follows. It should be a lack of third-party packages or frameworks to support some of the XML tags. Due to time constraints, we have shelved the XML integration combination node solution and continued to use the PY method to start it. We have added a specific startup command line in README (sensor_ip must be configured). Thank you for your continuous attention.

launch.invalid_launch_file_error.InvalidLaunchFileError: Caught exception when trying to load file of format [xml]: Unrecognized entity of the type: node_container
launch.invalid_launch_file_error.InvalidLaunchFileError: Caught exception when trying to load file of format [xml]: Unrecognized entity of the type: load_composable_node

[amc-nu]

Can you please paste the contents of your XML file?

[JianWangInno]

FYI

<launch>
  <arg name="sensor_model" description="Robin/Falcon"/>
  <arg name="return_mode" default="Dual" description="See readme for supported return modes"/>
  <arg name="frame_id"  default="innovusion"/>
  <arg name="sensor_ip" default="172.168.1.10" description="Lidar Sensor IP"/>
  <arg name="host_ip" default="172.168.1.11" description="Local IP"/>
  <arg name="data_port" default="8010" description="LiDAR Data Port"/>
  <arg name="cloud_min_range" default="0.4" description="Min Point Range"/>
  <arg name="cloud_max_range" default="2000.0" description="Max Point Range"/>
  <arg name="setup_sensor" default="true" description="Enable sensor setup on hw-driver."/>

    <node_container pkg="rclcpp_components" exec="component_container" name="innovusion" namespace="">
        <composable_node pkg="nebula_ros" exec="innovusion_driver_ros_wrapper_node" plugin="innovusion_driver_ros_wrapper_node" name="innovusion_cloud" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
        <composable_node pkg="nebula_ros" exec="innovusion_hw_interface_ros_wrapper_node" plugin="innovusion_hw_interface_ros_wrapper_node" name="innovusion_hw_driver" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="data_port" value="$(var data_port)"/>
            <param name="setup_sensor" value="$(var setup_sensor)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
        <composable_node pkg="nebula_ros" exec="innovusion_hw_monitor_ros_wrapper_node" plugin="innovusion_hw_monitor_ros_wrapper_node" name="innovusion_hw_monitor" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="data_port" value="$(var data_port)"/>
            <param name="setup_sensor" value="$(var setup_sensor)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
    </node_container>
</launch>

[amc-nu]

Thank you
Can I test this for with your branch?

[JianWangInno]

Of course you can. If you want to test whether the node_container tag in the XML startup file is available, we don't need our device to verify it. You can start it as follows:

ros2 launch nebula_ros my_launch.xml sensor_model:=Falcon

my_launch.xml contains the XML code posted above.

[amc-nu]

I found two main issues:

1. Since you want to use a composable node, you need to use plugin, not exec. Your file contains both, so it fails, the same would happen on a Python launch file.
2. The plugin name needs to be corrected. Please use the name in your CMakeLists.txt.

I didn't have a sensor, but I could launch successfully with the following file

<launch>
    <arg name="sensor_model" description="Robin/Falcon"/>
    <arg name="return_mode" default="Dual" description="See readme for supported return modes"/>
    <arg name="frame_id"  default="innovusion"/>
    <arg name="sensor_ip" default="172.168.1.10" description="Lidar Sensor IP"/>
    <arg name="host_ip" default="172.168.1.11" description="Local IP"/>
    <arg name="data_port" default="8010" description="LiDAR Data Port"/>
    <arg name="cloud_min_range" default="0.4" description="Min Point Range"/>
    <arg name="cloud_max_range" default="2000.0" description="Max Point Range"/>
    <arg name="setup_sensor" default="true" description="Enable sensor setup on hw-driver."/>

    <node_container pkg="rclcpp_components" exec="component_container" name="innovusion" namespace="">
        <composable_node pkg="nebula_ros" plugin="InnovusionDriverRosWrapper" name="innovusion_cloud" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
        <composable_node pkg="nebula_ros" plugin="InnovusionHwInterfaceRosWrapper" name="innovusion_hw_driver" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="data_port" value="$(var data_port)"/>
            <param name="setup_sensor" value="$(var setup_sensor)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
        <composable_node pkg="nebula_ros" plugin="InnovusionHwMonitorRosWrapper" name="innovusion_hw_monitor" namespace="">
            <param name="sensor_model" value="$(var sensor_model)"/>
            <param name="return_mode" value="$(var return_mode)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="sensor_ip" value="$(var sensor_ip)"/>
            <param name="frame_id" value="$(var frame_id)"/>
            <param name="host_ip" value="$(var host_ip)"/>
            <param name="data_port" value="$(var data_port)"/>
            <param name="setup_sensor" value="$(var setup_sensor)"/>
            <param name="cloud_min_range" value="$(var cloud_min_range)"/>
            <param name="cloud_max_range" value="$(var cloud_max_range)"/>
        </composable_node>
    </node_container>
</launch>