CoordinateLimitForce

[Vilhjálmur Grétar Elíasson]

Hello, I am in need of assistance regarding a project that I'm doing in OpenSim.

I'm trying to run a Static Optimization on a 2392 model which I have modified to have a prosthetic, transtibial foot. The foot is made from short cylindrical segments connected via joints and using CoordinateLimitForce to act as torsional springs, which simulate bending action.

So, I have modified the 2932 model, scaled it and added modified markers from a 2392 example, I ran an Inverse Kinematics and an Inverse Dynamics simulation which seem to work ,with somewhat high errors. But when its comes to the SO, it fails.

I get errors saying that some constraints regarding pelvic tilt are being violated greatly, although I never made any constraints.

It doesn't seem to matter if I lock the foot, omit external forces, fiddle with additional actuators or do anything that I can think of.

Does anybody have any idea what the problem is? Has anyone used CoordinateLimitForce, or any passive forces, and has some tips? I feel like my model should work.

Many thanks,

V