Design and Control of a Six Degrees-of-Freedom Magnetically Levitated Positioning System

Magnetic levitation technology is a promising solution to achieve ultraprecision motion in vacuum environment as it is with the characteristics, e.g., non-contact, frictionless, and unlimited stroke. This paper presents the design and control of a six Degrees-Of-Freedom (DOF) magnetically levitated (maglev) positioning system. The maglev positioner is implemented by using four groups of Halbach permanent magnet arrays and coil stators. Through energizing the three-phase current in four coil arrays, the six DOF Lorentz force will be generated in the translator of the maglev system to conduct positioning. To control the maglev positioning system, the controllers of X and Y-axes are designed and optimized according to the specifications characterizing on the closed-loop performance of the maglev system, where the specifications are formulated as the linear matrix inequalities (LMIs) in the constrains of the created optimization. Finally, the experiments are conducted on the maglev prototype to demonstrate its positioning performance of the maglev positioning system.