Problem of running inverse dynamics in AnyMocapModel

[yixing]

Hi Everyone,
I am using the “FullBody_GRFPrediciton” in AnyMocapModel files. I got an error at step 190 of inverse dynamic analysis. I did not change the model at all. Could you please tell me what the error is and how to debug it?
Thanks.

Yixing Liu

[toerholm (Søren Tørholm)]

Hi Yixing,

Which version of AMMR and AMS are you using?

Best regards
Søren

[yixing]

Hi,

I am using AMMR 2.1.1.
Thanks for reply.

Regards
Yixing Liu

[toerholm (Søren Tørholm)]

Hi Yixing,

I am sorry about this problem, we are able to replicate it.

The issue is that the interpolation functions used for the markers has some end effects due to filtering.
This introduce some artificial acceleration in the last frames which means the model is not able to create balance using the foot contact forces.

To fix this subtract some frames from the analysis.

• in the file TrialSpecificData_GRFPrediction.any
• add this line LastFrame = .C3DFileData.Header.LastFrameNo-3;

Hopefully this will resolve the problem.

Best regards
Søren

[yixing]

Hi,

Thanks a lot. Problem is solved.

Yixing Liu