Seagate Technology Incorporated

XingHui Huang

Kenneth A Haapala

Reed David Hanson

Dwight Russell Kinney

Ximin Shan

Systems and methods are disclosed for calibrating actuators in a multi-stage servo system. In certain embodiments, a method may comprise performing a calibration process on a multi-stage actuated servo system, including simultaneously injecting voltage injections into multiple microactuators of the servo system, measuring a resulting position error signal (PES), and determining gain settings for each of the multiple microactuators based on the PES. Multiple microactuators can therefore be calibrated during a single-injection calibration operation.

Calibration of multi-stage servo system

Systems and methods are disclosed for calibrating actuators in a multi-stage servo system. In certain embodiments, a method may comprise performing a calibration process on a multi-stage actuated servo system, including: seeking the multi-stage actuated servo system to a selected location, via a first stage actuator; providing a first voltage injection to a first microactuator of the multi-stage actuated servo system; measuring a first position error signal (PES) of the multi-stage actuated servo system; determining a first gain for the first microactuator based on the first PES, without adding a signal injection to the first PES; and applying the first gain to the first microactuator.

Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

Hysteresis compensation in a disc drive

A discrete Fourier transform (DFT) of a position error signal (PES) of a read/write head controlled by a currently-used controller is determined. A plurality of predicted PES spectra are determined based on the DFT of the PES and a plurality of sensitivity functions associated with a plurality of controllers. One of the plurality of controllers is selected based on respective deviation metrics of the plurality of PES spectra. Servo control of the read/write head changes to use the selected controller.

Growing community of inventors

Longmont, CO, United States of America

XingHui Huang