IMU plugin

[tongtybj]

I am considering to use imu plugin in gazebo.
What is the main difference between hector imu plugin and GazeboRosImuSensor?

[meyerj]

The GazeboRosImuSensor plugin was only added/merged recently (ros-simulation/gazebo_ros_pkgs#363), while the IMU plugin in hector_gazebo dates back to 2012. Back then there was no proper IMU plugin in ros-gazebo-pkgs, that

• includes gravity in the acceleration output, like real accelerometers would do,
• can simulate sensor drift and a non-zero initial bias,
• also applies an error to the orientation output, which is correlated to the simulated accelerometer drift, and
• is reconfigurable through dynamic_reconfigure and services at run-time to adjust the error parameters or to "calibrate" the IMU (reset the bias state to zero).

The approach of GazeboRosImuSensor, that uses Gazebo's ImuSensor internally, is definitely cleaner and should be preferred for new projects. But I have not compared the output of both plugins in detail yet. I think the last two "features" are still unique to hector_gazebo_ros_imu.

Another IMU plugin I am aware of is provided by the rotors_simulator.

[tongtybj]

@meyerj

Thank you for your kind explanation! I also agree that the last two features are important. Hope GazeboRosImuSensor can also implement these features.