help for CMC

[Hang Xu]

I ran the CMC for my gait simulation. I follow all the instruction,but it always have error like following:
rdCMC.computeControls: t = 1.23
SimTK Exception thrown at InteriorPointOptimizer.cpp:249:
Optimizer failed: Ipopt: Not enough degrees of freedom (status -10)
OPTIMIZATION FAILED...


rdCMC.computeControls: WARN- The optimizer could not find a solution at time = 1.230000.
If using the fast target, try using the slow target.
Starting at a slightly different initial time may also help.

I used the slow target to run CMC, it can work but the model become extremely distort not like walking at all. The interesting thing is I ran the g2354 used slow target, the model is also extremely distort. but it can walk very well used fast target.

I tried to change the <cmc-time-window> and Kp, Kv values, but it is the same error message appear.

does anyone meet the same situation when running the CMC?

I will appreciate if you have any idea about it

[Luca Modenese]

Hi,
I have exactly the same problem but I couldn't find a solution yet.

Luca

[Yu Zhang]

Hi,
I am user also. Did u check the kinematics_q.mot data in RRA Result? Is that all right?

[Yi Wang]

I think this introduction for all kinds of the error of IPOPT output would help to understand the specific error.

This is it. http://www.coin-or.org/Ipopt/documentation/node56.html

And this article of IPOPT would help you to understand of IPOPT better and deeper.

Not_Enough_Degrees_Of_Freedom:

Console Message: EXIT: Problem has too few degrees of freedom.
This indicates that your problem, as specified, has too few degrees of freedom. This can happen if you have too many equality constraints, or if you fix too many variables (IPOPT removes fixed variables).

So check the setting files and OpenSim trouble-shooting page at http://wiki.simtk.org/opensim/rraCmcPage would help.

All help came from Ayaman, Cheers guys.