I have been trying to use the CMC tool with MobL-ARMS Upper Extremity Model (the latest version) with my set of experimental data. I have been able to get the ik solution, the simulation run smoothly. However, when I try to use the CMC tool, after a few timesteps the model start dislocating and I start getting warning messages and then the error:
The inverse kinematic solution is for the elbow flexion-extension motion, however, looking at the simulations in the visualizer window, I noticed that the model does not try to rotate the elbow joint, but it does try to move the shoulder joints around, then the model looks dislocated. Please look at the image, that is how the model looks like when cmc fails, and as I mentioned before, I do get an ik solution to my task with minimum error.CMC.computeControls: t = 0.09
CMC::computeControls WARNING- small force range for DELT3 (0 to 0)
CMC::computeControls WARNING- small force range for TMIN (0 to 0)
CMC::computeControls WARNING- small force range for TMAJ (0 to 0)
CMC::computeControls WARNING- small force range for LAT1 (0 to 0)
CMC::computeControls WARNING- small force range for LAT2 (0 to 0)
CMC::computeControls WARNING- small force range for LAT3 (0 to 0)
CMC::computeControls WARNING- small force range for CORB (0 to 0)
CMC::computeControls WARNING- small force range for BICshort (0 to 0)
CMC::computeControls WARNING- small force range for ECU (0 to 0)
CMC::computeControls WARNING- small force range for EDCL (0 to 0)
CMC::computeControls WARNING- small force range for EDM (0 to 0)
Exception caught in Millard2012EquilibriumMuscle::calcMuscleDynamicsInfo from DELT1
Exception caught in Millard2012EquilibriumMuscle::calcFiberVelocityInfo from DELT1
SimTK Exception thrown at MuscleFixedWidthPennationModel.cpp:169:
Error detected by Simbody method MuscleFixedWidthPennationModel::calcPennationAngularVelocity: Fiber length cannot be zero.
(Required condition 'fiberLength > 0' was not met.)
Does anyone have any suggestion? I run the tutorial #6 that comes with the model and it runs ok. The task that comes with it is Reach.