Double Peak GRF's When Using A contact Model

[Brodie Klosowski]

Hello,

I have been trying to run a 3D walking tracked simulation that is based off of the 3D walking example however I have replaced the GRF reference file with a six sphere contact model found here: https://simtk.org/projects/predictsim_mtp (see attached image for reference).

The simulation runs and solves well and has accurate joint angles but the GRF's are strange and the vertical GRF has 4 peaks instead of two (See attached image for reference). If anyone has any idea on why this might be occurring I would be very grateful to here it.

zip file with all the relevant files such as model, MATLAB code, and results: https://drive.google.com/file/d/1RROLqr ... sp=sharing

Thanks in advance.

[Mohammadreza Rezaie]

Hi, you might need to add a MocoContactTrackingGoal to your problem. An example can be found in the example2DWalking.