Controller design and implementation of six-degree-of- freedom magnetically levitated positioning system with high precision

This paper presents the controller design and implementation of a high-precision six-degree-of-freedom (6-DOF) magnetically levitated (maglev) positioner. This high-precision positioning system consists of a novel concentrated-field magnet matrix and a triangular single moving part that carries three three-phase permanent-magnet planar-levitation-motor armatures. Since only a single levitated moving part, namely the platen, generates all required fine and coarse motions, this positioning system is reliable and potentially low-cost. The three planar levitation motors based on the Lorentz force law not only produce the vertical force to levitate the triangular platen but also control the platen's position and orientation in the horizontal plane. The main contribution of this paper is that all 6-DOF motions are solely controlled by magnetic forces without any other means to support the platen's weight against gravity, and the most suitable controller of the magnetic levitation system was designed and impleme...