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I have a question about inverseKinTraj class. It seems to return qsol as well as qdotsol and qddotsol and I would like to add velocity constraint on the time step. For example, I would like to add A(q(t))*qdot(t) = Constant and (q(t+1)-q(t))/dt=qdot(t+1). Is there any way I could impose velocity level constraints on the inverse kinematic trajectory?

Junhyeok Ahn
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inverseKinTraj doesn't offer the API for constraint A(q(t)) * qdot(t) = constant. Moreover, inverseKinTraj assumes that the trajectory is a piecewise cubic spline (namely it has continuous joint velocity/acceleration), so we cannot do the backward Euler integration (q(t+1) - q(t)) / dt = qdot(t+1), which doesn't give a continuous joint velocity/acceleration.

Hongkai Dai
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  • Thanks for the comment. I think for the aforementioned types of constraint, I should use ```SingleTimeLinearPostureConstraint``` and ```inverseKin``` with previous solution ```q_prev``` instead. For example, ```A(q_prev)*q_sol = constant * dt + A(q_prev)*q_qprev``` – Junhyeok Ahn Sep 04 '18 at 22:10
  • Yes, if `A(q(t))` could be a fixed matrix, then you can do `A(q_prev)*q_sol = constant * dt + A(q_prev)*q_qprev`. – Hongkai Dai Sep 05 '18 at 17:16