Return to neutral point in foot damping control

[Saeed-Mansouri]

Hi Dr. Caron,

As you stated in the paper, you implemented the foot damping control introduced by Kajita. However, the second term on the right-hand side of Eq (14) of Kajita's paper is not considered in the foot damping control applied in the LIPM controller. Why didn't you consider such a term?

[stephane-caron]

This term is implemented but in the IK task. In the task configuration, we have:

      "contact":
      {
        "damping": 300.0,
        "stiffness": 1.0,
        "weight": 10000.0
      },

We configure the task with high damping and low stiffness so that its top priority is to track desired velocities (themselves set by the CoPTask), and if possible return to the nominal foot pose. This stiffness therefore corresponds to the time constant T in equation (14) of Kajita et al.

[Saeed-Mansouri]

It was so helpful.