HEAD POSITIONING CONTROL METHOD AND SYSTEM
 Inventor: Kazuyuki Takita, Hachiohji, Japan
 Assignee: International Business Machines Corporation, Armonk, N.Y.
 Appl. No.: 227,588
 Filed: Aug. 2, 1988
 Foreign Application Priority Data
Aug. 6, 1987 [JP] Japan 62-195436
 Int. C1.5 G11B 5/55
 U.S. CI 360/78.07; 360/78.04
 Field of Search 360/78.04, 78.07, 78.12,
 References Cited
U.S. PATENT DOCUMENTS
4,068,269 1/1978 Commander et al 360/78.14
4,679,103 7/1987 Workman 360/78.14
4,775,903 10/1988 Knowles 360/77.04
FOREIGN PATENT DOCUMENTS
59119577 7/1984 Japan .
59146485 8/1984 Japan .
59146486 8/1984 Japan .
J. P. Mantey, "Offset Force Correction for Disk File", IBM TDB, vol. 21, No. 5, Oct. 1978, pp. 1792-1795. R. K. Oswald, "Design of a Disk File Head-Positioning Servo", IBM Journal of Res. & Dev., Nov. 1974, pp. 506-512.
C. Maury, "High Track Density for Magnetic Disk Drive with an 'Embedded Servo' Positioning System", IEEE Trans, on Magnetics, MAG-17, No. 4, Jul. 1981.
Primary Examiner—Vincent P. Canney
Assistant Examiner—David L. Robertson
Attorney, Agent, or Firm—Thomas R. Berthold
A data recording disk file, wherein head positioning servo information is located in sectors angularly spaced around the disk, utilizes an improved head positioning control system for data track following. The control system includes timing circuitry and head position detection circuitry for generating, respectively, a servo sector initiation signal and a signal representative of the head position relative to the centerline of the desired data track to be followed. The control system also includes a velocity detector for determining the velocity of the head relative to the data tracks, a microprocessor for computing an actuator input current signal for moving the actuator and the attached head so as to maintain the head on the desired data track between servo, and memory storage means for storing predetermined constants and values of previously measured head velocity and previously computed actuator input current signals. In response to the servo sector intiation signal, the microprocessor computs a new actuator input current signal based upon the new measured head position, the new measured head velocity, the previously measured head velocity, the previously computed actuator input current signal, and predetermined stored constants, and outputs this new current signal to the actuator. The microprocessor computation takes advantage of the fact that the disturbance to the position of the head during track following and between servo sectors is directly related to the difference between the actual acceleration of the head and the previously set head acceleration.
5 Claims, 7 Drawing Sheets