Currently, I am developing a plugin using the OpenSim API that creates a new custom joint. This joint is simply a spring with non-linear stiffness. This plugin is used in the ankle of a prosthetic leg. The plugin takes the ankle angle, and applies a torque that should return the foot to the zero position.
To take a better look at the behavior of the plugin, I tried to run forward dynamics simulations without a reserve actuator in the ankle. This causes the model to be unstable. Luckily, I found this discussion which suggests using a Correction Controller when an actuator is omitted in the forward dynamics: viewtopicPhpbb.php?f=91&t=10627&p=29478&start=0&view=
This indeed gives a stable simulation. However, I found that the excitation of the corrector in the ankle is still too high. I tried disabling the correction controller for this ankle only.
In the forward dynamics setup file (.xml), under the 'correction controller', there is a tag named 'actuator list' (see image below). It says that you can specify here the actuators that will be tracked by the Correction Controller. However, no matter what actuator name(s) I put here, I still get the same high ankle corrector force.
So my questions are:
-How do I disable a specific actuator from being corrected by the Correction Controller in FD simulations?
-What is the correct syntax when using the 'actuator_list' tag in the FD setup file?
-Could the correction controller be bugged? Or have I overlooked anything?
Thank you in advance,
Levi
Image of the Correction Controller (actuator chosen arbitrarily)
