Questions abot AnyGeneralForce

[BBJ (zhou)]

Hi

I downloaded the SitToStand model, could you tell me what the following code mean?
AnyFolder Robot_Human_Interactions =
{
CreateAnyGeneralForce6DOF Pelvis_Forces(
TargetFrame = Main.HumanModel.BodyModel.Trunk.SegmentsLumbar.PelvisSeg,
BaseFrame = Main.Model.EnvironmentModel.EXO_ROBOT.PELVIS_PART___1.HipJointCenterCoordSys)=
{
strength_Fx = 1000;
strength_Fy = 0;
strength_Fz = 1000;
strength_Mx = 1000;
strength_My = 1000;
strength_Mz = 1000;
};

The unit of strength is N, right, why the value of strength is 1000 and strength_Fy = 0? Could you explain it to me, thank you very much.

Best regards
BBJ

[pgalibarov]

Hi BBJ,

This code means that the robot-human interaction is modeled by 6 dof actuators (muscle of 1kN strength), where linear Y direction is disabled, since the muscle has the strength of 0. Meaning that something else has to carry the Y direction linear loads.

Regards,
Pavel

[BBJ (zhou)]

Hi Pavel

Thank you for your quick reply. What is the reference system of AnyGeneralForce6DOF? Is it the global reference system? If the Y direction is disabled, it means there is no relative movement in this direction, right? I found that the Y direction on the foot is not disabled. Could you explain it to me? Thanks again.

Best regards
BBJ

[pgalibarov]

Hi BBJ,

The ref. frame is BaseFrame. The disabled Y direction means that there is no force transfer in this direction. And the opposite for the foot.

Regards,
Pavel