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robotology / icub-models

Official URDF and SDF models of the iCub humanoid robot.
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iCub >= V2.6 urdfs have the imu frame oriented as the V2.5 #230

Closed Nicogene closed 5 months ago

Nicogene commented 5 months ago

Today @martinaxgloria and I noticed that the imu_frame disappeared when I made the PR in icub-models-generator that exports the sensors frames:

head_imu_0 took its place, but the problem is that this frame does not incorporate the additionalTransformation from the old imu frame (iCub v2.5) to the frame of the rfe.

You can see that in iCub 2.5 and 2.7 they have the same orientation.

https://github.com/robotology/icub-models/blob/453d9ed52f01a8a92cf41a9cae14ddb669446d5c/iCub/robots/iCubGazeboV2_5/model.urdf#L986-L992

https://github.com/robotology/icub-models/blob/453d9ed52f01a8a92cf41a9cae14ddb669446d5c/iCub/robots/iCubGazeboV2_5/model.urdf#L2684

https://github.com/robotology/icub-models/blob/453d9ed52f01a8a92cf41a9cae14ddb669446d5c/iCub/robots/iCubGazeboV2_7/model.urdf#L986-L992

https://github.com/robotology/icub-models/blob/453d9ed52f01a8a92cf41a9cae14ddb669446d5c/iCub/robots/iCubGazeboV2_7/model.urdf#L2700

If we read from the real imu and compare what we read in simulation we should notice this discrepancy

cc @traversaro @pattacini

Nicogene commented 5 months ago

Today I tried to export the urdf without the exportFrameInURDF, we obviously miss the head_imu_0 frame but we have the imu_frame link and the sensors seems oriented correctly.

V2_5

  <gazebo reference="head">
    <sensor name="head_imu_0" type="imu">
      <always_on>1</always_on>
      <update_rate>100</update_rate>
      <pose>0.009500000190735 0.133444 0.009299999999999996 -1.5707963267948963 1.5707963267948963 0.0</pose>
      <plugin name="iCub_yarp_gazebo_plugin_IMU" filename="libgazebo_yarp_imu.so">
    <yarpConfigurationFile>model://iCub/conf/gazebo_icub_inertial.ini</yarpConfigurationFile>
</plugin>
    </sensor>
  </gazebo>
  <sensor name="head_imu_0" type="accelerometer">
    <parent link="head"/>
    <origin rpy="-1.5707963267948963 1.5707963267948963 0.0" xyz="0.009500000190735 0.133444 0.009299999999999996"/>
  </sensor>

V2_7

  <gazebo reference="head">
    <sensor name="head_imu_0" type="imu">
      <always_on>1</always_on>
      <update_rate>100</update_rate>
      <pose>0.023453700190734995 0.20544400000000002 -0.023077900000000023 1.5707963267948997 -3.4914813388431334e-15 0.0</pose>
      <plugin name="iCub_yarp_gazebo_plugin_IMU" filename="libgazebo_yarp_imu.so">
    <yarpConfigurationFile>model://iCub/conf/gazebo_icub_inertial.ini</yarpConfigurationFile>
</plugin>
    </sensor>
  </gazebo>
  <sensor name="head_imu_0" type="accelerometer">
    <parent link="head"/>
    <origin rpy="1.5707963267948997 -3.4914813388431334e-15 0.0" xyz="0.023453700190734995 0.20544400000000002 -0.023077900000000023"/>
  </sensor>

So probably it is the exportFrameInURDF is somehow problematic.

Nicogene commented 5 months ago

This PR fixes this problem:

Unfortunately the exportFrameInURDF shadows the exportedFrames option, this is due that we are using as key of the map the CREO name that is in common between the two options, then now the sensor is correctly oriented, but imu_frame is missing.

On the other hand, imu_frame has to be kept in the yaml in order to express the additional transformation

martinaxgloria commented 5 months ago

So, the frame name for the imu in the urdf is still head_imu_0 after this fix but now contains the addition transform, right?

cc @Nicogene

Nicogene commented 5 months ago

So, the frame name for the imu in the urdf is still head_imu_0 after this fix but now contains the addition transform, right?

cc @Nicogene

Exaclty

V2_5

  <link name="head_imu_0"/>
  <joint name="head_imu_0_fixed_joint" type="fixed">
    <origin xyz="0.009500000190735 0.133444 0.009299999999999996" rpy="-1.5707963267948961 1.570796326794896 0"/>
    <parent link="head"/>
    <child link="head_imu_0"/>
    <dynamics damping="0.1"/>
  </joint>

V2_7

  <link name="head_imu_0"/>
  <joint name="head_imu_0_fixed_joint" type="fixed">
    <origin xyz="0.023453700190734995 0.20544400000000002 -0.023077900000000023" rpy="1.5707963267948997 0 0"/>
    <parent link="head"/>
    <child link="head_imu_0"/>
    <dynamics damping="0.1"/>
  </joint>
martinaxgloria commented 5 months ago

Great, thank you!

Nicogene commented 5 months ago

Closing since now V2_5 and V2_6/7 have the frames oriented differently