Method and apparatus for predicting failure of a disk drive

• US 5,557,183 A
• Filed: 02/17/1995
• Issued: 09/17/1996
• Est. Priority Date: 07/29/1993
• Status: Expired due to Term

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Bates, Randall M., Wadkins, Patricia J., Larson, Thomas S., Glaess, David F.
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US08/391,313
• Time in Patent Office: 578 Days
• Field of Search: 318/434, 318/568.15, 361/23, 361/24, 361/28, 361/30, 361/31, 361/33, 361/86, 361/88, 361/91, 360/71, 360/73.01, 360/73.03, 360/73.04, 360/73.08, 360/74.1, 360/75, 360/77, 360/78.04, 360/78.05, 360/78.06, 364/474.17, 364/474.19
• US Class Current: 318/434
• CPC Class Codes: G11B 19/00 Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
• CPC Class Codes: G11B 19/06 by counting or timing of machine operations
• CPC Class Codes: G11B 19/20 Driving; Starting; Stopping; Control thereof
• CPC Class Codes: G11B 20/1816 Testing

Abstract

Disclosed is a disk drive having a spindle motor, a disk that is rotated by the spindle motor, and a movable actuator arm that carries a read/write head. The head physically engages a parked, or home, position at the Inner Diameter (ID) of the disk when the spindle motor is not energized and the disk is stationary. The electrical energization that must be applied to the spindle motor in order to breakaway the head from the disk (i.e., the breakaway current), and the energization that is necessary to cause the motor to achieve a stable spinning state (i.e., the spin current) are monitored. Possible future failure of the disk drive is predicted as a function of any changes in these two electrical parameters, as these parameters may change over a period of time; i.e., may change over a number of disk drive stop/start events.

Claims

1. A method for predicting failure of a disk drive, comprising the steps of;

providing a disk drive having an electrical spin motor, a disk that is rotated by said spin motor, and a head that physically engages said disk when said spin motor is not energized,

monitoring, for a plurality of stop/start events, the electrical energization applied to said spin motor to cause said head to breakaway from said physical engagement with said disk,

predicting the possibility of a future failure of said disk drive as a function of said monitored electrical energization applied to said motor in said plurality of stop/start events,

determining a rate of increase of said monitored electrical energization applied to said motor in said plurality of stop/start events, and

predicting the possibility of future failure of said disk drive as a function of said determined rate of increase.

2. The method of claim 1 wherein said step of determining a rate of increase of said monitored electrical energization applied to said motor in said plurality of stop/start events, and said step of predicting the possibility of future failure of said disk drive as a function of said determined rate of increase, occur only when said plurality of disk drive stop/start events exceed a given number.

3. A method for predicting failure of a disk drive, comprising the steps of;

manufacturing a disk drive having an electrical spindle motor, a disk that is rotated by said motor, and a head that physically engages said disk when said motor is not energized,

measuring during said manufacturing step a breakaway electrical energization parameter that must be applied to said motor in order to cause said head to breakaway from said physical engagement with said disk,

storing said breakaway electrical energization parameter determined during said measuring step,

periodically determining during data processing use of said disk drive a breakaway electrical energization parameter that must be applied to said motor in order to cause said head to breakaway from said physical engagement with said disk,

comparing said stored breakaway electrical energization parameter determined during said manufacturing step to said breakaway electrical energization parameter periodically determined during data processing use,

predicting the possibility of a future failure of said disk drive as a function of said comparison,

storing the magnitudes of said periodically determined breakaway electrical energization parameters,

determining a rate of increase of said stored magnitudes of said periodically determined breakaway electrical energizations, and

predicting the possibility of a future failure of said disk drive as a function of said determined rate of increase.

4. The method of claim 3 wherein said step of determining a rate of increase of said stored magnitudes of said periodically determined breakaway electrical energization parameters, and said step of predicting the possibility of a future failure of said disk drive as a function of said determined rate of increase, occur only when said periodic determinations exceeds a given number.

5. Apparatus for predicting failure of a disk drive having a motor, a disk that is rotated by said motor, and a head that physically engages said disk when said motor is not energized, comprising;

means for monitoring, for a plurality of stop/start events, the electrical energization magnitude applied to said motor to cause said head to breakaway from said physical engagement with said disk,

means for predicting the possibility of a future failure of said disk drive as a function of said electrical energization magnitude,

means for storing said electrical energization magnitude applied to said motor for said plurality of start/stop events,

means for determining a rate of increase for said stored electrical energization magnitudes, and

means for predicting the possibility of a future failure of said disk drive as a function of said determined rate of increase.

6. Apparatus for predicting failure of a disk drive having a motor, a disk that is rotated by said motor, a head that physically engages said disk when said motor is not energized, and memory means containing a prior motor energization parameter that was operative to cause said head to breakaway from said physical engagement with said disk, said apparatus comprising;

means for periodically monitoring a motor energization parameter that is presently operable to cause said head to breakaway from said physical engagement with said disk,

means for predicting the possibility of a future failure of said disk drive as a function of said prior motor energization parameter and said presently monitored motor energization parameter,

means for storing the magnitudes of said periodically monitored motor energization parameters, and

means for predicting the possibility of a future failure of said disk drive as a function of a rate of change of said stored magnitudes.

7. A disc drive having a preventive diagnostic apparatus, said disc drive having a motor, a disk that is rotated by said motor, and a head that physically engages said disk when said motor is not energized, said preventive diagnostic apparatus comprising;

means for monitoring, for a plurality of stop/start events, the electrical energization applied to said motor to cause said head to breakaway from said physical engagement with said disk,

means for predicting the possibility of a future failure of said disk drive as a function of said monitored electrical energization,

means for storing each of a plurality of said monitored electrical energizations,

means for determining a rate of increase for said plurality of stored monitored electrical energizations, and

means for predicting the possibility of a future failure of said disk drive as a function of said determined rate of increase.