US Patent No: 6,219,198

Number of patents in Portfolio can not be more than 2000

State estimator alteration for odd sample times in a disk drive servo control system

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Abstract

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A direct access storage device (DASD) servo control system includes a servo controller that makes an estimate of disk actuator arm position and velocity as for a regular, expected PES signal sample time, and then alters the estimate for an odd sample time using a simplified estimation function. The altered estimate is generated after determining the amount of time by which the odd sample time is longer than the regular sample time. An odd sample time event is recognized and the odd sample time is forced longer than the regular sample time by skipping a disk control signal computation interval. In this way, the estimated position and velocity of the disk arm is improved for odd sample times, even where the change in one PES sample time may be unrelated to the change in any subsequent PES sample times.

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Patent Owner(s)

Patent OwnerAddressTotal Patents
HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.AMSTERDAM1333

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Dobbek, Jeffrey Joseph San Jose, CA 7 96
Ho, Peter Kui Morgan Hill, CA 5 13
Serrano, Louis Joseph San Jose, CA 43 682

Cited Art Landscape

Patent Info (Count) # Cites Year
 
HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V. (4)
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4,816,941 Disk file digital servo control system with optimized sampling rate 37 1987
5,381,282 Inter-sample switching of servo control in direct access storage devices 24 1991
5,392,290 System and method for preventing direct access data storage system data loss from mechanical shock during write operation 40 1992
 
CIT GROUP/BUSINESS CREDIT, INC. (3)
5,089,757 Synchronous digital detection of position error signal 58 1991
5,206,570 Actuator servo compensation method 9 1991
5,202,821 Sampled-data control system exhibiting reduced phase loss 9 1991
 
INTERNATIONAL BUSINESS MACHINES CORPORATION (3)
4,835,632 Disk file digital servo control system with multiple sampling rate 26 1987
5,270,880 Predictive read-write inhibit decision using fuzzy logic 26 1992
5,241,433 Disk drive servo control 33 1992
 
HEWLETT-PACKARD COMPANY (1)
4,775,903 Sampled servo seek and track follow system for a magnetic disc drive 45 1986
 
HITACHI GLOBAL STORAGE TECHNOLOGIES JAPAN, LTD. (1)
5,313,340 Read/write controlling apparatus for adjusting the data length of a magnetic disk 31 1992
 
HITACHI, LTD. (1)
5,132,854 High speed seek sector servo magnetic disk drive unit 13 1989
 
KABUSHIKI KAISHA TOSHIBA (1)
5,959,797 Magnetic recording apparatus having means for reading data associated with a non-readable servo sector 4 1997
 
Konica Corporation (1)
4,724,370 Servo system for a disk drive 15 1986
 
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. (1)
5,383,068 Head position recognition method, a speed calculation method, and a head movement speed control device 22 1992
 
MINISTOR PERIPHERALS INTERNATIONAL LIMITED (1)
5,576,909 Method for positioning a data transducer head in a rotating disk drive data storage device 58 1995
 
NEC CORPORATION (1)
4,982,297 Head positioning system for compensating for erroneous detection of recorded position error information 24 1988
 
SAMSUNG ELECTRONICS CO., LTD. (1)
5,940,239 Velocity/position estimator of magnetic head in magnetic disk driving apparatus 13 1996
 
TEAC CORPORATION (1)
5,208,710 Method for high speed positional control of a transducer for rotating disk data storage apparatus 2 1990

Patent Citation Ranking

Forward Cite Landscape

Patent Info (Count) # Cites Year
 
HGST NETHERLANDS B.V. (1)
7,787,748 Recording and reproducing apparatus, content reproducing apparatus, magnetic disk device, and control method thereof 0 2003
 
HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V. (1)
6,700,728 Method and disk drive for enhanced performance in the presence of stationary PES outliers 1 2001
 
INTERNATIONAL BUSINESS MACHINES CORPORATION (1)
6,865,052 Apparatus and method to calibrate servo sensors in a noisy environment 4 2002
 
KABUSHIKI KAISHA TOSHIBA (1)
7,027,254 Head positioning control method, device for disk device and disk device 4 2000
 
SEAGATE TECHNOLOGY LLC (1)
7,319,570 Random vibration and shock compensator using a disturbance observer 16 2005