Loaded walking RRA issue.

[Ali Khalilianmotamed Bonab]

To whom it may concern,
I asked my question in OpenSim general forum and since I could not get an answer about the issue, I decided to post it specifically here.

Based on the model of loaded walking, there are two different coordinates named "knee_angle_r_beta" and two constraints on them which I do not understand why it is added to this model and I would appreciate if someone can explain them.

Furthermore, When I am performing, first, scaling tool and then RRA tool on this model without any modifications on the model setting, the model cannot track the kinematics and gives a high error, the only error that RRA gives to me is mentioned below and the model's behavior has been attached as a video. I would be grateful if someone can help me to fix this problem.

opensim_video_2.zip

(749.94 KiB) Downloaded 18 times

Additionally, when I am disabling the constraints, this error is not appearing and kinematics tracking error is decreasing, However, the error is still remarkable.

Code: Select all

AssemblySolver::track() attempt Failed: SimTK Exception thrown at assembler.cpp:973:
  Method Assembler::track() failed because:
Unable to achieve required assembly error tolerance.
Assembly error tolerance achieved: 8.4324322211032546e-09 required: 1e-10.
Model unable to assemble: AssemblySolver::assemble() Failed: SimTK Exception thrown at assembler.cpp:897:
  Method Assembler::assemble() failed because:
Unable to achieve required assembly error tolerance.
Assembly error tolerance achieved: 8.4324322208105915e-09 required: 1e-10.
Model relaxing constraints and trying again.