> Ah, this is the tricky part, it is the velocity of the end-effector-frame with
> expressed int the base-frame of the chain (right before the first joint) but
> with it's reference point at the end-effector(to make sure that rotations are
> around the endeffector point)

ok, but is the reference point at the end-effector equal to the third frame according to this message:

"A Twist does not have an absolutely fixed reference frame: you use it to
represent the velocity of one frame with respect to another frame,
expressed with respect to still another THIRD frame"

or is it a reference frame which is composed of the translational part of the base frame and the rotational part of the end-effector frame, linke this:

Frame(Vector(translational component of base frame),Rotation(rotational component of end effector frame))?

Another question would be:

Can I put the output-Twist of KDL::Path_Line:: Twist Vel (double s, double sd) directly into the input-Twist-Parameter of KDL::ChainIkSolverVel_pinv::CartToJnt (const JntArray &q_in, const Twist &v_in, JntArray &qdot_out) or is ist necessary to transform first?