Control of Highly Precise Actuator with PZT and Displacement Expander for Evaluation of Magnetic Recording

Abstract

A spin stand which is used to evaluate read-write performance of magnetic heads and media can not become able to allow thermal drift of its mechanism and run out of its air spindle motor. Accuracy and mechanical stiffness of the spin stand supported the highly precise measurement of the magnetic recording. However, as an allowable tracking error will reach within 10nm, the future spin stand will need track follow with a fine actuator. A new PZT actuator which has characteristic of a resonance frequency 3.31 kHz and a displacement 7.24μm/50V has been manufactured. The analysis of the structure using FEM (finite element method) and control performance of the PZT actuator via the displacement feedback control system with DSP (Digital Signal Processor) has been discussed.