AssemblySolver error

[Mohammadreza Rezaie]

Hi,

I'm interested in using this model but unfortunately, I can't run Scale, IK, RRA, and other tools. The error says that there is a problem with AssemblySolver.assemble(). I read that the constrains (WeldConstraints: Lat_Cond_r_Constraint and Lat_Cond_l_Constraint) cause this error and if I disable these constrains, the tools run successfully.

Code: Select all

java.lang.RuntimeException: AssemblySolver::assemble() Failed: SimTK Exception thrown at Assembler.cpp:871:
  Method Assembler::assemble() failed because:
Optimizer failed with message: SimTK Exception thrown at InteriorPointOptimizer.cpp:261:
  Optimizer failed: Ipopt: Infeasible problem detected (status 2)
Assembly error tolerance achieved: 0.00676450655554198 required: 1e-005.
	at org.opensim.modeling.opensimModelJNI.OpenSimContext_processModelMarkerPlacer__SWIG_0(Native Method)
	at org.opensim.modeling.OpenSimContext.processModelMarkerPlacer(OpenSimContext.java:329)
	at org.opensim.tracking.ScaleToolModel$ScaleToolWorker.construct(ScaleToolModel.java:348)
	at org.opensim.swingui.SwingWorker$2.run(SwingWorker.java:108)
[catch] at java.lang.Thread.run(Thread.java:745)

I was wondering if you would guide me to solve this issue.

Your help is much appreciated.

Cheers,
Mohammadreza

[Todd Leutzinger]

Hello Mohammadreza,
You may need do use a different version of the model based on what version of OpenSim you are using. If using Opensim 4.0 you have to use an updated model, not the one found in the paper. You should be able to find the 4.0 model in a different topic in this forum.

[Mohammadreza Rezaie]

Hello Todd,

Thanks for your answer and I appreciate it.

I ran the original model in OpenSim 3.3 which I suppose they are compatible with each other. Is there any solution for this version?
Does it need any plugin that the constraints work well? If no, how did the model work for the authors?

Regards,
Mohammadreza

[Mohammadreza Rezaie]

Finally, the problem was solved.

In the "Example_Scale_Settings.xml" file, the "sagittal_articulation_frame_" body was scaled based on the shank measurements and thus had different scale factor relative to "femoral_cond", "med_cond", and "lat_cond". I was following this example file that I faced the error. By selecting the same scale factor based on thigh measurements, it worked properly.

Cheers,
Mohammadreza