simtk.org

hello,
recently I worked on static optimisation in order to perform a forward dynamic, But the activations that I get doesn't give the solution that I expected.
So I have use the CMC to have good solution with the forward dynamic.
In the user help, the reason is that when the muscles is weak, we have to use some actuators to help them. And that what CMC done.
My question is : if the muscles are too strong, how can you do?

Hi,

If you increase the max isometric force of the muscles, you may have similar issues. That is because, you scale both the active and passive components of the muscle. So, if you are in a configuration, some passive forces will be enormous, so the effect will be the same, meaning you will need extra actuation. This is a difficult problem to address, and the parameters of the muscles should be altered with caution.

You can't generate a forward simulation that will be stable for a long time without some kind of controller. Nevertheless, I would suggest you to check RRA + CMC + FD.

Regards

Thanks for your help. So there is not a muscle parameter that I can increase in order to have best results with forward dynamic without actuators contributions?

You can tune the muscle parameters, but it is not straightforward how you will define their values.

hi,
OK, I get it.I will do it with actuators. Thanks.