November 15, 2012
The Revolute Joint
A revolute joint doesn’t affect the translational motion at all.
A revolute joint can represent a hinge or a drive, depending on how it is being connected.
If the joint represents a hinge, the external torque at the joint is zero.
The joint computes the relative angle between frame_a and frame_b, and from it, computes the orientation matrix that is needed to determine the coordinate transformation from frame_a to frame_b.