Permanent Maglev Platform Using a Variable Flux Path Mechanism: Stable Levitation and Motion Control

This article presents a three degrees of freedom (3-DOF) permanent maglev platform for a cleanroom conveyor system supported by four magnetic poles that utilize a variable flux path mechanism. Since the magnetic force of poles is generated and controlled entirely by the rotation of disk-type permanent magnets (PMs), the system exhibits a quasi-zero power consumption and anti-adsorption capability. First, the system mechanism is illustrated, and the magnetic force of the variable flux path pole is measured. Then the mathematical model and state-space of the maglev platform are established based on dynamic analysis. Afterward, a double closed-loop controller is designed for stable levitation and motion control, and the coordinate transformation matrix is used to decouple the control system. Finally, the simulations and experiments were implemented, and stable levitation and 3-DOF motion control were realized with a remarkable positioning precision. The results indicate that the controller and decoupling strategy are effective.