Nonlinear Compensator Design of Active Proximity Sliders for Head-Disk Spacing Variation Suppression in 3-nm Air Bearings

Based on the concept that the FH of a portion of the slider that carries the read/write element can be adjusted by a piezoelectric actuator and the FH can be measured according to the magnetic signal, a new 3-DOF analytic model and an observer-based nonlinear compensator are proposed to achieve ultra-low FH with minimum modulation under short range attractive forces. Numerical simulations show that the FHM due to disk waviness is effectively reduced with a control voltage of less than ±2V.Copyright © 2004 by ASME