CMC Warning

[Zheqi Hu]

Hi there,

I'm calculating muscle forces with CMC tool, and error occurs. Muscle forces at specific time cannot be calculated.

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CMC::computeControls WARNING- small force range for per_long_r (0 to 0)

CMC::computeControls WARNING- small force range for tfl_l (0 to 0)

CMC::computeControls WARNING- small force range for ercspn_l (0 to 0)

SimTK Exception thrown at InteriorPointOptimizer.cpp:264:
Optimizer failed: Ipopt: Infeasible problem detected (status 2)
OPTIMIZATION FAILED...


CMC.computeControls: ERROR- Optimizer could not find a solution.
Unable to find a feasible solution at time = 0.7.
Model cannot generate the forces necessary to achieve the target acceleration.
Possible issues: 1. not all model degrees-of-freedom are actuated,
2. there are tracking tasks for locked coordinates, and/or
3. there are unnecessary control constraints on reserve/residual actuators.


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So I'm wondering what I should do to solve this problem. I have checked the possible issues. All model degrees-of-freedom are actuated.

Any advice would be helpful. Thank you.

[Thomas Uchida]

Have you tried the suggestion on the "Getting Started with CMC" page in the Confluence documentation, under CMC Troubleshooting, item 1 (https://simtk-confluence.stanford.edu/d ... eshooting:)?

[Ali Khalilianmotamed Bonab]

Dear Dr. Thomas K. Uchida,
Hi,
I am also facing this problem while I am trying to reproduce the result of paper titled " Muscle Contributions to fore-aft and vertical body mass center accelerations over a range of running speeds". I read your post on GitHub "Fix CMC slowdown due to reassembly of model within CMCActuatorSubsystem " to solve this issue and also tried the Opensim Manual.
Since I am naive in using the opensim, I could not find .CPP files to modefy them. I would appreciate you, if you help me to fix this problem step by step.
Sincerely,
Ali.