Standing model foot fix

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1

Hi, everyone.

I used AMMR v2.2, AnyBody.7.2.
I used StandingModel and modified hip and knee flexion so that the result is under picture.
image

I want to fix the foot location because I want to use GRF-prediction, so how can I fix the foot and modified the knee and hip flexion?

2

Hi

The standing model has drivers to the ground, has these been disabled?
If not please try to run the model and see what happens?

I suspect the image is the loading position before any constraints are being solved, please confirm
this .

Best regards
Søren

3

Hi, Søren!

When I try to run this model, I get these messages "GHRot : Close to singular position : Orientation close to Gimbal Lock, i.e., first and third axis of rotation being parallel", "Study.InverseDynamics : Muscle recruitment solver : solver aborted due to singular KKT matrix".

image

There is no change in the model.

Best regards
JunHyeon

4

Hi JunHyeon,

This error is a sign that the muscle recruitment can not find a way to balance the model.

Please describe the modifications you have made to the StandingModel,

Secondly please also describe exactly what you would like the model to do? is it a posture or dynamic motion you want to model?

Best regards
Søren

5

Hi, Søren!
Thank for your reply.

Fisrt, I just modified HipFlexion, KneeFlexion in the Mannequin.any file.

Second, I want to modify HipFlexion and KneeFlexion with model's feet fixed to the ground for using GRF-prediction.

Best regards
JunHyeon

6

Hi JunHyeon,

If the only changes you made to the model is in the mannequin file then i think it should work unless the values are too extreme so that the model can not hold it balance.

To test i took the standard model and change the hipflexion and kneeflexion in the mannequin.any file.

  HipFlexion = 50.0;
  HipAbduction = 5.0; 
  HipExternalRotation = 0.0;
  KneeFlexion = 40.0;

This picture displays the outcome. These two changes was the only changes i made to the standard model.

image

Best regards
Søren

7

Hi, Søren!

I made a new StandingModel and it solved the problem.

Maybe, I modified other variables.
Thank you for reply!

Best regards
JunHyeon

8

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