Data storage device re-qualifying state estimator while decelerating head

摘要

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.

主权项

1. A data storage device 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, wherein 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 at least: generating an initial state estimate of the head at the beginning of the servo fault; decelerating the head open-loop using a model-based deceleration control in response to the initial state estimate; while decelerating the head, re-qualifying the state estimator before the head reaches zero velocity; and after re-qualifying the state estimator and before the head reaches zero velocity, seeking the head to a target track closed-loop using the state estimator.