CMC Failing after Manually Scaling Model

Tamara Ordonez · Post by **Tamara Ordonez** » Mon Mar 18, 2019 10:03 am

I have an upper extremity model that focuses on the right arm muscles from the elbow to the hand. When I try to manually scale it with a factor greater than 1.02, the CMC fails before reaching completion. The task is basically Thumb Tip Pinch Force from 5N to 40N, from 0 to 3 seconds. I have changed the Pinch Force file to go from 10N to 40N, but it still fails. The message I receive is:

CMC.computeControls: ERROR- Optimizer could not find a solution.
Unable to find a feasible solution at time = 0.83.
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.