DRCSIM: Hand torque sensor - no X output

Create issue
Issue #247 resolved
John Hsu created an issue

Posted by Alberto Romay

The X component from the torque sensor of the hand is buggy. Z and Y components of the torque sensor in the wrist are giving an output while X is not. Discovered that only when the joint limits from the r_arm_mwx joint are reach the X starts giving an output.

Hand torque sensor 1 shows how the Z component is performing well, while the X is giving an output only when it reaches the joint limit (2:40).

Hand torque sensor 2 shows how the X component gives output only in the joint limits (upper 0:31 and lower 3:20).

Comments (7)

  1. Alberto Romay

    Hi John,

    Unfortunately It has not been resolved. I have tested with nightly from today May 8th and the X component seems to have a little bit more variation as before, however, the values in the X component are still a lot lower in comparison to Y and Z. I can see Z having values around 9 N-m when having the drill lifted and with the right palm pointing to the floor which I would expect from X when pointing the right palm to the left, but instead I am receiving values smaller than 1 N-m.

  2. John Hsu reporter

    it appears bad parsing of gazebo extension and gazebo extension ends up generating two <physics> blocks:

    <physics>
      <ode>
        <provide_feedback>0</provide_feedback>
        <cfm_damping>1</cfm_damping>
      </ode>
    </physics>
    <physics>
      <ode>
        <provide_feedback>1</provide_feedback>
        <cfm_damping>0</cfm_damping>
      </ode>
    </physics>  
    

    which ends up calling Joint::ApplyDamping even if cfm_damping is set to true. As a result, Joint::ApplyDamping resets Joint::forceApplied and thus, torque about the actuated joint is very small.

    This is fixed by this gazebo pull request.

  3. Log in to comment