Disable IMU orientation output

[iche033]

Signed-off-by: Ian Chen ichen@osrfoundation.org

Depends on:

• Add API for enabling / disabling IMU orientation gazebosim/gz-sensors#142
• Parse new param for enabling / disabling IMU orientation output gazebosim/gz-sim#899
• Check imu orientation field gazebosim/ros_gz#168

Updates the imu system to disable publishing orientation data.

• Update: an <enable_orientation>0</enable_orientation> SDF element is now added to individual models.. We will also need to update all the robot models on fuel.

With this change, the orientation values in the ROS imu msg should now be zeros, and the first element of the orientation_covariance field is set to -1 as per ROS imu msg documentation.

To test, launch any world with a UAV robot, e.g.:

ign launch -v 4 competition.ign worldName:=simple_cave_01 circuit:=cave robotName1:=X4 robotConfig1:=X4_SENSOR_CONFIG_1

and echo the imu msg to see that the orientation is now zeros:

rostopic echo /X4/imu/data

Example output:

header: 
  seq: 12506
  stamp: 
    secs: 50
    nsecs:  32000000
  frame_id: "X1/base_link/imu_sensor"
orientation: 
  x: 0.0
  y: 0.0
  z: 0.0
  w: 0.0
orientation_covariance: [-1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
angular_velocity: 
  x: 0.000139300054549
  y: 5.63009660877e-05
  z: -0.000108313959937
angular_velocity_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
linear_acceleration: 
  x: -0.0891951904981
  y: -0.0936655693381
  z: 9.87060748913
linear_acceleration_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

[m3d]

What is this PR about?! (2 days after closing qualification??) Does it mean the we will not get IMU orientation data anymore???!

[zbynekwinkler]

Isn't it past feature freeze time as described on https://github.com/osrf/subt/wiki front page, which is set to "May 25 - September 24"?

[nkoenig]

This is targeting the master branch, not the final_event branch. This code is not going to effect SubT finals.

[peci1]

Why did this change affect all robots? Most decent IMUs (like the Xsense MTI-30 we use) normally output orientation computed by an internal integrated filter.