gazebo harmonic imu sensor Gazebo plugin read sensor data World add plugin in world level1 2 3 4<plugin filename="gz-sim-imu-system" name="gz::sim::systems::Imu"> </plugin> Link add sensor at link level1 2 3 4 5 6<sensor name="imu_sensor" type="imu"> <always_on>1</always_on> <update_rate>1</update_rate> <visualize>true</visualize> <topic>imu</topic> </sensor> Reference gazebo tutorial sensor sdf