Re: MocoOrientationTrackingGoal
Posted: Wed Sep 23, 2020 8:05 am
I was doing tracking simulation with Ross Miller's 2D Model with implicit multibody dynamics. One issue was in setting the initial guess . By default, the implicit derivatives were not there in the initial guess. So, to get a compatible initial guess I used createGuess(). However I could not find a way to include the tracked states into the initial guess. So I inserted the states trajectory from the previous solution with explicit dynamics as suggested by Ross.
With this approach the solver could not converge within 2000 iterations. I also tried starting from the createGuess() and only setting the tendon forces to be of low value. This also didn't converge within 2000 iterations. Ross Miller also mentioned that he could not get good results with implicit multibody dynamics. I am also wondering why is it so, since implicit dynamics is supposed to have better convergence.
With this approach the solver could not converge within 2000 iterations. I also tried starting from the createGuess() and only setting the tendon forces to be of low value. This also didn't converge within 2000 iterations. Ross Miller also mentioned that he could not get good results with implicit multibody dynamics. I am also wondering why is it so, since implicit dynamics is supposed to have better convergence.