Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism – Controlling the head
Reexamination Certificate
2005-12-20
2005-12-20
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
Controlling the head
C360S061000
Reexamination Certificate
active
06977793
ABSTRACT:
A disk drive with a dual-stage actuator has a servo control system with two controllers. One controller is a dual-stage controller that simultaneously generates a primary actuator control signal and a secondary actuator control signal, and uses a degraded-stability primary actuator controller design with high low-frequency open-loop gain and a secondary actuator controller design that provides stability and high mid-frequency to high-frequency open-loop gain resulting in increased bandwidth. The other controller is a single-stage controller that generates only a primary actuator control signal and uses a stable VCM-only controller design. The single-stage controller is selected if failure of the secondary actuator is detected. Failure of the secondary actuator is detected either by providing a model of the dynamic response of the primary and secondary actuators and comparing the modeled head-position with the measured head-position, or by measuring the position of the secondary actuator relative to the primary actuator with a relative-position sensor and comparing the relative position to a modeled position of the secondary actuator.
REFERENCES:
patent: 5936805 (1999-08-01), Imaino
patent: 5959808 (1999-09-01), Fan et al.
patent: 6611399 (2003-08-01), Mei et al.
L.S. Fan et al., “Electrostatic Microactuator and Design Considerations for HDD Applications”, IEEE Transactions on Magnetics, vol. 35, No. 2, Mar. 1999, pp. 1000-1005.
Y. Lou et al., “Dual-Stage Servo With On-Slider PZT Microactuator for Hard Disk Drives”, IEEE Transactions on Magnetics, vol. 38, No. 5, Sep. 2002, pp. 2183-2185.
T. Semba et al., “Dual-stage servo controller for HDD using MEMS microactuator”, IEEE Transactions on Magnetics, vol. 35, Sep. 1999, pp. 2271-2273.
M. T. White et al., “Use of the Relative Position Signal for Microactuators in Hard Disk Drives”, Proceedings of the American Control Conference, Denver, Colorado, Jun. 4-6, 2003, pp. 2535-2540.
White Matthew T.
Yamamoto Satoshi
Berthold Thomas R.
Hitachi Global Storage Technologies - Netherlands B.V.
Hudspeth David
Negrón Daniell L.
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