Western Digital Technologies, Inc.

Shreekant Gayaka

Min Chen

Wei Xi

Young-Hoon Kim

A disk drive is disclosed comprising a head, a disk surface comprising servo information, and a dual stage actuator (DSA) servo loop comprising a voice coil motor (VCM) servo loop comprising a VCM and a microactuator servo loop comprising a microactuator operable to actuate the head over the disk surface. A position error signal (PES) is generated based on the servo information, and a first control signal is generated based on the PES. The first control signal is adjusted based on a function of the first control signal to generate a second control signal that compensates for a gain variation of the microactuator, and the microactuator is controlled based on the second control signal.

Disk drive compensating for microactuator gain variations

A disk drive is disclosed comprising a head, a disk surface, and a dual stage actuator (DSA) servo loop comprising a voice coil motor (VCM) servo loop comprising a VCM and a microactuator servo loop comprising a microactuator operable to actuate the head over the disk surface. A microactuator compensator processes a position error signal (PES) to generate a first control signal, and a disturbance sinusoid is injected into the first control signal to generate a second control signal, wherein the microactuator is controlled in response to the second control signal. Feed-forward compensation is generated corresponding to the injected disturbance sinusoid, and a third control signal is generated in response to the PES and the feed-forward compensation, wherein the VCM is controlled in response to the third control signal. A gain of the microactuator is estimated in response to the feed-forward compensation.

Growing community of inventors

Sunnyvale, CA, United States of America

Shreekant Gayaka