Remove FDK in SpineFixationwithFDK model

Hi everyone,

I am currently learning how to use SpineFixationWithForceKinematics model. I want to compare the influence of the FDK properties in Anybody. Thus, I set
#define BM_SPINE_RHYTHM ON
//InverseDynamics.ForceDepKinOnOff=On;
Anybody gives me message"Kinematically over-constrained". Does anyone know where I am wrong?

Thank you very much!

Hi Amin,

I think there might be an extra driver in the Drivers.any that causes that.

Please move the following block into the #ifdef#endif block.


  // negligible motion between sacrum and pelvis
  AnyKinEqSimpleDriver SacrumPelvisDriver = {
    AnySphericalJoint &Jnt = Main.HumanModel.BodyModel.Trunk.JointsLumbar.SacrumPelvisJnt;
    DriverPos = pi/180*{0.0, 0.0, 0.0};
    DriverVel = pi/180*{0.0, 0.0, 0.0};
    Reaction.Type = {Off, Off, Off};
  };  


This imperfection is corrected in the next versions of AMMR.

Kind regards,
Pavel

Hello Pavel,

Thank you very much. It works now. If I remove this, there will be no driver for SacrumPelvis joint. However, as far as I am concerned, spine rhythm have nothing to do with Pelvis(I read the PPT from other posts). My question is why we do not need this driver?

Thanks,

Amin

Hi Amin,

The spine rhythm has had this driver incorporated since a very long time ago. But yes, technically speaking it could be removed from the rhythm. Possibly will be done in the future, but it will stay like that for now. Normally it is not a problem.

Regards,
Pavel