Reaction force reference frame

Hi -

The piece of code below is from the joints & drivers file for a whole-body ingress/egress model that I have created. Is the resulting reaction force (Fout) defined with respect to the global coordinate frame or the 1st reference frame (LabCoordRef) that I’ve defined? And does the order of the moments still follow the default rotation sequence (z, y, x)?

Thank you,
Suzanne

AnyKinEqInterPolDriver PelvisGroundDriver ={ // interpolates btw data pts spaced in time
// translation measure (3D vector) used to drive pelvis, position of ref frame wrt lab ref frame
AnyKinLinear lin ={
AnyFixedRefFrame &ref1 =…EnvironmentModel.LabCoordRef;
AnyRefNode &ref2 = …HumanModel.Trunk.SegmentsLumbar.PelvisSeg.PelvisCoordSys;
Ref = 0;
};
// measures 3D rotation/orientation,orientation of pelvis seg wrt global ref frame
AnyKinRotational rot ={
AnyFixedRefFrame &ref1 =…EnvironmentModel.LabCoordRef;
AnyRefNode &ref2 = …HumanModel.Trunk.SegmentsLumbar.PelvisSeg.PelvisCoordSys;
Type=RotAxesAngles; // orientation measured by Cardan angles
};
Data={
Main.Model.EnvironmentModel.LocDataFolder.PelvisPosX,
Main.Model.EnvironmentModel.LocDataFolder.PelvisPosY,
Main.Model.EnvironmentModel.LocDataFolder.PelvisPosZ,
Main.Model.EnvironmentModel.LocDataFolder.PelvisRotZ,
Main.Model.EnvironmentModel.LocDataFolder.PelvisRotY,
Main.Model.EnvironmentModel.LocDataFolder.PelvisRotX
};
T=Main.Model.EnvironmentModel.LocDataFolder.GlobalTime;
Type=Bspline;
BsplineOrder = 4;

Reaction.Type={On,On,On,On,On,On}; // type specification of reaction forces
};

Hi Suzanne,

As you used Ref=0 in the linear measure, it means the the reference frame is the first given. And the rotation sequence is still the default one (z y x) because you did not define anything else, you could change it by specifying Axis1, Axis2 and axis3 if you want it.

Best regards.