importing the external real moment data using template model

Main Forum
1

Hi this is Bokku Kang from S. Korea.

I am running the kinematic tool using FDK module.

I got external raw moment data file and want to apply to the anybody template model(ex:human standing model). But I got error message like this;;
“Parameter has an invalid value for this interpolation; extrapolations are not allowed.”

Actually before I applied to the template model, I tried to the simple segment model I built and it worked well.

I think it is due to the conflict between the time of raw moment data and kinematics.SolverType.

I want to know why this happended and how to solve this problem.

Thank you!

code:

AnyFolder Drivers =
{
AnyKinEqSimpleDriver Driver1 ={
AnySphericalJoint &ref= Main.HumanModel.BodyModel.Right.Leg.Jnt.Hip ;
DriverPos={0,0,0}; //This is the initial guess on the position
DriverVel={0,0,0};
CType = {ForceDep,ForceDep,ForceDep}; //The constraint type is set to be force dependent so it will find the
//position with equilibrium
Reaction.Type={Off,Off,Off}; //The reactions are swicthed off here because otherwise the spring and forces would
//just be taken up by this reaction
};

};

AnyFolder ForceMoment =
{
AnyMoment3D Moment ={
AnyFunInterpol MomentFunction ={
Type=Bspline;
FileName = “AnyTestData.any”;
};
AnyRefNode &ref2= Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh.HipJoint;
AnyVector Mmt = MomentFunction(t);
Mlocal={Mmt[0],Mmt[1],Mmt[2]};
};
};

raw data file:

0.02500 -0.13800 7.38497 0.34600
0.03333 0.05052 6.84871 0.30942
0.04167 -0.09474 5.99487 0.28902
0.05000 -0.23182 5.33356 0.27488
0.05833 -0.33254 4.78900 0.25409
0.06667 -0.38619 4.34841 0.22659
0.07500 -0.38530 3.99596 0.19333
0.08333 -0.32358 3.70761 0.15626
0.09167 -0.21000 3.48676 0.11554
0.10000 -0.03726 3.28364 0.07583

1 Like
2

Dear Bokku,

  1. If you see the interpolation issue such as ‘Parameter has an invalid value for this interpolation; extrapolations are not allowed.’, then the tStart and tEnd values in your AnyBodyStudy object should be in the range of the time range in your external file.
    For your external file, the minimum t value is 0.02500 and the maximum t value is 0.10000. So I would recommend you to setup your tStart bigger than 0.02500 and your tEnd smaller than 0.10000.

  2. I don’t know what you would like to do exactly. But FDK is not aimed for running the full forward dynamics. It seems that you want to apply the external torque in the hip joint to see how the human behaviour is changing. But that is the area of forward dynamics. FDK assumes the quasi-static situation where both velocity and acceleration are almost zero, which are very very small. For your case, FDK may not be the best to use.

Best regards,
/MJ