Magnetically levitated six degree of freedom rotary table

This paper presents a novel six degree of freedom magnetically levitated rotary table. Benefits of magnetic levitation include frictionless movement allowing for high precision movements, and real-time correcting capability of 6-axis motion errors. The 6DOF actuator includes a circular Halbach magnet array attached to the underside of the moving table and a printed flat coil installed on the stator. The forces are generated by current through stationary coils interacting with the field from permanent magnet array. Position feedback is achieved using four capacitive probes and four optical encoders. The table has been manufactured and controllers for each axis have been designed. Movement has been demonstrated with position resolution of 55 nm (RMS).