Abstract
This paper describes a design and performance of a capacitive position sensing in the axial direction of a one-axis-controlled magnetic bearing, which requires in-process displacement measurement and position control of a spindle. The rotor position is measured using a differential variation of capacitance between the rotor and stator. The measurement method is based on the Abbe's principle. A magnetic bearing structure for -the capacitive position sensing is proposed and designed. Experimental results show that resolution of the capacitive position sensing is a micrometer in 10 kHz bandwidth and 20 μm range.
