Thanks for the reply! The problem remains when the contact mesh and elastic foundation force are removed, regrettably. This, even simpler, model has the same problem. What could be wrong? Is there an (undocumented) fundamental flaw/restriction in the CMC system, or a bug in its implementation? Is th...

Is there no one that can help me in what I think is a flaw in OpenSim/CMC?
Thanks in advance, Sietse.

For almost a year I am struggling with a model and CMC. I asked on this list and filed issues on opensim-core, but still no solution. I now am repeating my last issue #3679 here because I don't know anything else to do :( . The model is not too complicated: Joints: 1 slider, 4 pin, 2 custom (doing t...

Yes, thanks alot for that!
(sorry for the late response)

It sounds a bit dramatic, but I really am stuck with my CMC project. I created a few opensim-issues (see issue #3522) and asked on this forum, but the problem still is not solved. I created a model and trajectory as simple as possible that fails. This is both on Windows and Linux. The model consist ...

Because I somehow think that not using muscles is the problem here I changed the CoordinateActuator in the lower PinJoint into 2 muscles. withmuscle.png But it does not make any difference in the behavior, the balljoint becomes unstable just the same! I don't know what to do next. Where can I turn t...

Hello list, Cannot get CMC to work with my model. The problem is that the error in the position (joint angles) is NOT driven to zero, so CMC does not seem to be working! I asked on this list and posted an issue (#3345) on opensim-core, but no reaction at all. I really don't know what to do now apart...

I simplified the model even further, but the instabilities remain! There now remain only 2 bodies, a pin-joint and a ball-joint. opensim_snapshot.png For more details please see the last message of my issue 3345 from opensim-core. It includes the model, the trajectory and a video of the problem. Ple...

I found a few articles which simulated a person with an exoskeleton using CMC. So apparently it should work, also when using only generalized actuators in a joint. But my simple model, both on windows and linux, does not! I really want/need to make this work! The first step is to get a conformation ...

Hello List, It seems that CMC does not always work if there are joints not controlled by muscles but only with coordinate actuators (think motors). Like with an exo-skeleton, or someone with an artificial arm or leg. In my use case, a rower in a rowing boat, I come across it in developing it, becaus...