Western Digital Technologies, Inc.

Wenlin Zhang

Wei Xi

Orhan Beker

Yanan Huang

Yiqian Li

Xiao Ma

A data storage device is disclosed comprising a microactuator configured to actuate a head over a disk. A control signal applied to the microactuator is generated based on an input sequence u(k). A Preisach bit map bis updated based on the input sequence u(k), wherein the Preisach bit map bcorresponds to a Preisach plane modeling a hysteretic response of the microactuator. A current compensation value yis generated based on an update value generated based on: where hrepresents a slice of the Preisach plane and {circumflex over (b)}is an update bit map based on at least part of the Preisach bit map b. The current input uand the current compensation value yare combined to generate the control signal applied to the microactuator.

Data storage device compensating for hysteretic response of microactuator

A data storage device is disclosed comprising a disk comprising a plurality of tracks defined by servo sectors, a head, and a servo controller configured to servo the head over the disk based on an estimated state generated by a state estimator. The servo controller is configured to execute a seek operation to seek the head over the disk and recover from a servo fault during the seek operation by generating an initial state estimate of the head at the beginning of the servo fault, and decelerating the head open-loop using a model-based deceleration control in response to the initial state estimate. While decelerating the head, the state estimator is re-qualified before the head reaches zero velocity, and after re-qualifying the state estimator and before the head reaches zero velocity, a seek operation is executed to seek the head to a target track closed-loop using the state estimator.

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Irvine, CA, United States of America

Wenlin Zhang