ROS2 IRIS Rp_lidar gazebo simulation sensor data unavailable

ROS / MAVROS / MicroDDS
1

Hello!
I want to use iris rplidar model in gazebo simulation to test collision avoidance algorithms in forest-like environment. I am using ros2 framework for this but however I am unable to get the camera and lidar data on ros2 topics list.

I successfully launched the gazebo simulation using make px4_sitl gazebo-classic_iris_rplidar, after this I connect the ros2 mircodds to using micro-ros-agent udp4 --port 8888 command. Now from here I can easily control the drone using a ros2 package. But I cannot get the lidar and image data as ros2 topics.

When I do ros2 topic list following list is displayed
/fmu/in/obstacle_distance /fmu/in/offboard_control_mode /fmu/in/onboard_computer_status /fmu/in/sensor_optical_flow /fmu/in/telemetry_status /fmu/in/trajectory_setpoint /fmu/in/vehicle_attitude_setpoint /fmu/in/vehicle_command /fmu/in/vehicle_mocap_odometry /fmu/in/vehicle_rates_setpoint /fmu/in/vehicle_trajectory_bezier /fmu/in/vehicle_trajectory_waypoint /fmu/in/vehicle_visual_odometry /fmu/out/failsafe_flags /fmu/out/sensor_combined /fmu/out/timesync_status /fmu/out/vehicle_attitude /fmu/out/vehicle_control_mode /fmu/out/vehicle_global_position /fmu/out/vehicle_gps_position /fmu/out/vehicle_local_position /fmu/out/vehicle_odometry /fmu/out/vehicle_status /parameter_events /rosout

I can see the sensor data using gazebo topic visualisation.

From the previous topic I see that it is a plugin issue but I couldn’t get an idea how to solve it.

2

@Rugved_katole I don’t think it is expected to publish lidar topics to ros2

You need to check whether the gazebo rplidar plugin should be publishing to ros2 or not: PX4-SITL_gazebo-classic/model.sdf at 5610c3fb441a2f3babc8ad7a63c8c4ce3e40abfa · PX4/PX4-SITL_gazebo-classic · GitHub

3

Thanks for your reply.

I tried to do that
I changed it as given in ros2 Migration guide But still I am unable to get them as ros2 topics. My sdf file for rplidar is as follows.

<?xml version="1.0" ?> 
    <inertial>
      <pose>0 0 0 0 0 0</pose>
      <mass>0.19</mass>
      <inertia>
        <ixx>4.15e-6</ixx>
        <ixy>0</ixy>
        <ixz>0</ixz>
        <iyy>2.407e-6</iyy>
        <iyz>0</iyz>
        <izz>2.407e-6</izz>
      </inertia>
    </inertial>

    <visual name="visual">
      <geometry>
        <box>
          <size>0.02 0.05 0.05</size>
        </box>
      </geometry>
    </visual>

    <sensor name="laser" type="ray">
      <ray>
        <scan>
          <horizontal>
            <samples>360</samples>
            <resolution>1</resolution>
            <min_angle>-3.14</min_angle>
            <max_angle>3.14</max_angle>
          </horizontal>
        </scan>
        <range>
          <min>0.2</min>
          <max>6</max>
          <resolution>0.05</resolution>
        </range>
        <noise>
          <type>gaussian</type>
          <mean>0.0</mean>
          <stddev>0.01</stddev>
        </noise>
      </ray>
      <plugin name="laser" filename="libRayPlugin.so" />
      <plugin name="gazebo_ros_head_rplidar_controller" filename="libgazebo_ros_ray_sensor.so">
        <ros>
          <topicName>laser/scan</topicName>
          <!-- <remapping>~/out:=scan</remapping> -->
        </ros>
        <output_type>sensor_msgs/LaserScan</output_type>
      </plugin>
      <always_on>1</always_on>
      <update_rate>10</update_rate>
      <visualize>true</visualize>
    </sensor>
  </link>
</model>

I am very new to using the gazebo plugins. If you could point out what changes I need to make to get it as ros2 topics, it would be great.