Spatial transfer of conductive plate through decoupling of two axial electrodynamic forces generated by magnet wheel

The partial shielding of the magnetic field generated by a magnet wheel that rotates under a conductive plate generates two linearized axial electrodynamic forces similar to those generated by a linear induction motor on the plate over the non-shielded open area. The forces are strongly coupled by the rotating speed of the magnet wheel, which is the only control variable. Therefore, to position the plate in space as desired, another control variable besides the wheel speed is needed. So, in this paper, the absolute size of the open area is proposed as a new variable. Around the nominal rotating speed, the normal force is much more sensitive than the thrust force to the speed of the wheel. Therefore, the speed roughly corresponds to the normal force, and the size of the open area corresponds to the thrust force. Of course, a variation of the normal force due to a change in size of the open area should be compensated by controlling the wheel speed. As another case for the positioning of a conductive plate, the in-plane positions of the plate can be controlled indirectly by out-of-plane control with respect to the target air–gaps obtained by the in-plane controller. Although the only controlled variable is the air–gap lengths, in-plane control forces are reflected in determining the air–gap lengths. The above methods are verified experimentally.