US 2003/0206365 A1 · Reducing actuator arm oscillation during settle mode in a disc drive servo system

Abstract

An apparatus and method for compensating actuator arm oscillation induced by resonance mode excitation during a seek in a disc drive data handling system. The actuator arm supports a head adjacent a recording surface, and a servo loop controls the position of the actuator arm. A frequency of actuator arm oscillation is identified, after which a seek is initiated to move the head from an initial track to a destination track on the recording surface. A position error signal (PES) is generated to indicate position of the head relative to the destination track, and a compensation signal is generated by a filter based on the PES and the frequency of oscillation of the actuator arm. The compensation signal is adapted to remove a component of the PES arising from the actuator arm oscillation, and is applied to the servo loop as the head is settled onto the destination track.

Claims11

Dependent claims

In a data handling system which uses an actuator arm to support a head adjacent a recording surface and a servo loop to controllably move the actuator arm, a method for canceling an actuator arm oscillation induced by a resonance mode excitation of the actuator arm, comprising steps of:

(a) identifying a frequency of actuator arm oscillation induced by the resonance mode excitation;
(b) initiating a seek to move the head from an initial track to a destination track on the recording surface;
(c) receiving a position error signal indicative of a position of the head relative to the recording surface;
(d) generating a compensation signal based on the position error signal and the frequency of the actuator arm oscillation and adapted to remove a component of the position error signal arising from the actuator arm oscillation;
and
(e) applying the compensation signal to the servo loop as the head is settled onto the destination track.

3 more elements

A data handling system, comprising:

a recording surface on which a plurality of nominally concentric tracks are defined;
an actuator assembly comprising an actuator arm which supports a head adjacent the recording surface;
and
a servo circuit coupled to the actuator assembly, comprising:
a servo controller which controls position of the head in response to a position error signal indicative of a position of the head with respect to the recording surface, the servo controller configured to perform a seek operation to move the head from an initial track to a destination track;
and
a filter operably coupled in parallel with the servo controller to receive the position error signal and to generate a compensation signal during a settle mode as the head is brought over the destination track, the compensation signal based on the position error signal and a frequency of actuator arm oscillation induced by resonance mode excitation during the seek, the compensation signal adapted to cancel a component of the position error signal arising from the oscillation.

4 more elements

Dependencies are inferred from the claim text.

Reducing actuator arm oscillation during settle mode in a disc drive servo system

Life of this patent

Reducing actuator arm oscillation during settle mode in a disc drive servo system

Life of this patent

Abstract

Claims11