simtk.org

Hi,
I have been trying to run a CMC simulation on the MoBL_ARMS upper extremity model.
I initially scaled the model and ran IK. The .mot file generated in IK was used to run CMC, along with a
few tweaks in the tasks as well as constraint files. On initializing, I got the following error messages on the GUI:
Unable to find a feasible solution at time = 0.
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.

Just as a test, I ran CMC on the scaled model that came as default with the MoBL_ARMS package, and used the default constraints and task files.
However, I received the exact same error on trying to execute the tool (On OpenSim 3.3 and 4.0). Has anybody successfully used the tool on the default as well as a custom MoBL_Arms model? I'd appreciate any suggestions.
Thanks!

Hi Aushim,

Did you manage to solve this problem? We are facing the same problem as you mentioned. Any help would be appreciated.

Thank you,

Regards,

Rejin

Well , I don't know if this information is useful for you both, but I tried the tutorials 5 and 6 that comes with the model and they ran ok.
I'm also having trouble using CMC with my experimental data, it crashes and when I run the Inverse Dynamics obviously I get unrealistic shoulder moments (~400Nm). If you have any updates on how to use the model, it would be very helpful if you could share it.

Thanks! Good luck!