Friction cone constraint in Quadruped PyMPC

[Batou1406]

Error in enforce_force_constraints from Quadruped PyMPC

The function enforce_force_constraints doesn't restrain forces to the friction cone, but rather to the friction pyramid. Thus the friction isn't properly limited. If a µ=0.5 wants to be imposed, this function would let a force corresponding to µ=0.71 (if Fx=Fy=0.5*Fz). Fixing this should be straightforward and has already been implemented in orbit. The problem is this would require some refactor of the variables name. Not urgent for now, but to keep track.

• [x] Correct the behaviour with a proper cone constraints

[Batou1406]

Implemented in torch and in jax