Multiple IMU sensors with imu_sensor_broadcaster

[delihus]

During making an example with multiple ROSbots I cannot separate IMU sensors for each robot. Ignition system of 2 robots reads the value of the imu from one sensor. How to create multiple sensors with imu_sensor_broadcaster?
This is URDF where namespace_ext is rosbot1/ or rosbot2/:

 <ros2_control name="${namespace_ext}imu" type="sensor">
    <hardware>
      <plugin>rosbot_hardware_interfaces/RosbotImuSensor</plugin>
      <param name="connection_timeout_ms">120000</param>
      <param name="connection_check_period_ms">500</param>
    </hardware>

    <sensor name="${namespace_ext}imu">
      <state_interface name="orientation.x" />
      <state_interface name="orientation.y" />
      <state_interface name="orientation.z" />
      <state_interface name="orientation.w" />
      <state_interface name="angular_velocity.x" />
      <state_interface name="angular_velocity.y" />
      <state_interface name="angular_velocity.z" />
      <state_interface name="linear_acceleration.x" />
      <state_interface name="linear_acceleration.y" />
      <state_interface name="linear_acceleration.z" />
    </sensor>
  </ros2_control>

  <gazebo reference="imu_link">
    <sensor name="${namespace_ext}imu" type="imu">
      <plugin filename="ignition-gazebo-imu-system" name="ignition::gazebo::systems::Imu"></plugin>
      <always_on>true</always_on>
      <update_rate>25</update_rate>
      <topic>imu/data_raw</topic>
      <visualize>false</visualize>
      <enable_metrics>false</enable_metrics>
      <frame_id>imu_link</frame_id>
      <ignition_frame_id>imu_link</ignition_frame_id>
      <ros>
        <namespace>${namespace}</namespace>
      </ros>
    </sensor>
  </gazebo>

Configuration

ROS 2 Humble

Reproduce

The example you can run from here https://github.com/husarion/rosbot_ros/tree/add-namespaces following the README and then run in terminal 1:

ros2 launch rosbot_gazebo simulation.launch.py namespace:=rosbot1

In the second terminal:

ros2 launch rosbot_gazebo spawn.launch.py namespace:=rosbot2 y:=2 x:=1

Here is the video with the issue. On the right side you can see the plots with orientation w and z. When the second robot spawns the values of the /rosbot1/imu_broadcaster are shadowed.
Screencast from 28.11.2023 16:18:00.webm

[azeey]

The IMU system/plugin should not be initialized for each robot. You just need one <plugin filename="ignition-gazebo-imu-system" name="ignition::gazebo::systems::Imu"></plugin> in the world .sdf file and remove the <plugin> tags from each <sensor>.

[delihus]

The IMU system/plugin should not be initialized for each robot. You just need one <plugin filename="ignition-gazebo-imu-system" name="ignition::gazebo::systems::Imu"></plugin> in the world .sdf file and remove the <plugin> tags from each <sensor>.

Thank you for that. I will check that!

The other question is how spawn properly multiple robots where the plugin configs are in the robot's urdf?

[azeey]

The other question is how spawn properly multiple robots where the plugin configs are in the robot's urdf?

Plugins such as DiffDrive are meant to be specific to a robot, so you should be okay spawning multiple robots each with it's own plugin. But plugins such as IMU are meant to be initialized at the world level.

[delihus]

I have added the plugin loading to worlds and it worked.
husarion/husarion_gz_worlds@461dafa