Adding backlash in the tendon-level

Discussion in 'Modeling' started by Mincheol, Oct 20, 2020.

  1. Hi,

    I'm trying to make a realistic model for my robot on MuJoCo.

    My robot is tendon-driven with compliant tendons, and of course there is substantial backlash in the tendon-level.

    Currently, I see that there's a way to model backlash at the joint-level by defining a virtual joint in addition to the actual joint that sort of adds discontinuity in the joint movement,

    but if I implement that in my model, it does not model the backlash correctly because mine is in tendon-level.

    So I was wondering if there is any trick that can be done for tendon-level backlash that is similar to adding a virtual joint.

    Thank you so much!
  2. I also found that this example does not really model backlash from the actuator side.

    If I perturb the joint with an external force, backlash seems to be working, not affecting the actuator.
    But if I move the actuator, although it shouldn't move the joint due to the backlash, the joint follows the actuator movement right away.

    Perhaps I'm missing something here. Could someone help?