excitation vs. activation
Posted: Wed Oct 31, 2012 5:09 pm
Hi
My name is Ana, and I am a reconverted aerospace engineer trying to learn about muscles.
I have been reading about Musculotendon Actuator Dynamics, and this are composed of "activation dynamics" and "musculotendon contraction dynamics", which are assumed to be decoupled. If I well understood, the inputs and the outputs are:
- Activation dynamics (first order process) :
Input: excitation u(t)
Output: activation a(t)
- Musculotendon contraction dynamics (first order process):
Input: activation a(t)
Output: muscle force(t) = tendon force (t)
One of the outputs of CMC are the "actuator controls", which are calculated after the Static Optimization step. Are these "controls" referring to excitation u(t), or activation a(t)? I understood this seems to be confusing for a lot of people, so hopefully this is going to be helpful for a lot of people?
I guess the calculation of forces(t) from the activation a(t) is included in the Forward Dynamic step. Is this correct? Is there some documentation/paper to know more about this calculation/equations (musculotendon contraction dynamics)? I am reading Zajac 1989, but I am still having some trouble with this part.
Thanks!
Ana
My name is Ana, and I am a reconverted aerospace engineer trying to learn about muscles.
I have been reading about Musculotendon Actuator Dynamics, and this are composed of "activation dynamics" and "musculotendon contraction dynamics", which are assumed to be decoupled. If I well understood, the inputs and the outputs are:
- Activation dynamics (first order process) :
Input: excitation u(t)
Output: activation a(t)
- Musculotendon contraction dynamics (first order process):
Input: activation a(t)
Output: muscle force(t) = tendon force (t)
One of the outputs of CMC are the "actuator controls", which are calculated after the Static Optimization step. Are these "controls" referring to excitation u(t), or activation a(t)? I understood this seems to be confusing for a lot of people, so hopefully this is going to be helpful for a lot of people?
I guess the calculation of forces(t) from the activation a(t) is included in the Forward Dynamic step. Is this correct? Is there some documentation/paper to know more about this calculation/equations (musculotendon contraction dynamics)? I am reading Zajac 1989, but I am still having some trouble with this part.
Thanks!
Ana