CMC failed

[Zhen Yang]

Hi!

Does anyone know what it means with this error message below?

"CMC.computeControls: t = 1
SimTK Exception thrown at InteriorPointOptimizer.cpp:261:
Optimizer failed: Ipopt: Restoration failed (status -2)
OPTIMIZATION FAILED..."

What should I change to make CMC work?

Thanks!
Zhen

[Ayman Habib]

Hi Zhen,

Please consult the documentation page on our help portal
http://simtk-confluence.stanford.edu:80 ... +Practices

and let us know how it goes or if you continue to have questions.

Best regards,
-Ayman

[Zhen Yang]

Hi Ayman,
in the documentation it states:

"If CMC is failing, try increasing the maximum excitation for reserves and residuals by orders of magnitude until the simulation runs, then try working your way back down while also "relaxing" tracking weights on coordinates."

In which file can I change the maximum excitation for reserves and residuals?

Thanks,
Zhen

[Zhen Yang]

Hi,

I got another message which I don't know how to fix
“WARN- small force range for peri_r (0 to 0)”

Is there anyone who knows how to change this?

Thanks,
Zhen

[Ayman Habib]

Hi Zhen,

If you're using the output from RRA to run CMC then you'll have a file of RRA_Actuators.xml (similar to the gait2354_RRA_Actuators.xml included with the distribution). These are the reserves and residuals . You can change the <optimal_force> there.

The small force warning is benign and can be ignored.

Hope this helps,
-Ayman

[Zhen Yang]

Hi Ayman!

Thanks for your reply, but I got this small force warning through whole simulation time at each every step, are they still benign? If not how do I fix it?
I read about changing optimizer from ipopt to CFSQP. But OpenSim doesn't have CFSQP.

Thanks,
Zhen