Hi, I noticed that the active fiber force-length curve in OpenSim DegrooteFregly2016Muscle does not match the Millard2012EquilibriumMuscle; the later one is wider, the max force is at optimal fiber force, and it matches the experimental data very well (Link). I'm also familiar with the active_force_width_scale method, but it expands the left side more the the right side.
I engaged in some curve fitting to improve the parameters, and this is the result:
And this is the peak:
As can be seen, the optimized curve matches the Millard curve very well, and the peak value is exactly at the optimal fiber length. I'm sharing the parameters here:
Hi, I noticed that the active fiber force-length curve in OpenSim
DegrooteFregly2016Muscledoes not match theMillard2012EquilibriumMuscle; the later one is wider, the max force is at optimal fiber force, and it matches the experimental data very well (Link). I'm also familiar with theactive_force_width_scalemethod, but it expands the left side more the the right side.I engaged in some curve fitting to improve the parameters, and this is the result:
And this is the peak:
As can be seen, the optimized curve matches the Millard curve very well, and the peak value is exactly at the optimal fiber length. I'm sharing the parameters here:
Hope this helps.