System and method for monitoring friction between head and disk to predict head disk interaction failure in direct access storage devices
First Claim
1. A system for predicting failure of a storage system including:
- first means for moving an element over a surface, said surface moving relative to said element and said first means including an arm for supporting said element over said surface and a motor connected to said arm;
second means for detecting a change in a lateral force applied to said element and for providing a signal in response thereto, wherein said lateral force comprises a frictional force and a windage force, said second means including means for calculating said windage force; and
third means for processing said signal and predicting a failure of the storage system in response thereto.
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Accused Products
Abstract
A system for predicting the failure of a storage unit, such as a disk drive. In a most general sense, the inventive system includes a first mechanism (20, 22, 24) for moving an element (16) over a surface (12) which is moving relative to the element (16). The first mechanism includes an arm (18, 20) for supporting the element (16) over the surface (12) and a motor (24) connected to the arm (18, 20). A position error detector (42) is included for detecting a change in torque applied to the motor (24) due to friction between the element (16) and the surface (12). The position error detector (42) provides a signal in response to changes in torque which is processed to predict a head disk interaction or failure of the storage system. In a particular embodiment, the position error detector (42) senses a change in a lateral force applied to the element (12) in response to a change in friction between the surface and the element. In a typical application, the storage unit is a disk drive, the surface is a disk on which a storage medium is disposed and the element is a magnetic head. In an alternative embodiment, changes in friction between the head and the medium are sensed by sensing changes in the motor current required to maintain disk speed.
55 Citations
16 Claims
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1. A system for predicting failure of a storage system including:
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first means for moving an element over a surface, said surface moving relative to said element and said first means including an arm for supporting said element over said surface and a motor connected to said arm; second means for detecting a change in a lateral force applied to said element and for providing a signal in response thereto, wherein said lateral force comprises a frictional force and a windage force, said second means including means for calculating said windage force; and third means for processing said signal and predicting a failure of the storage system in response thereto. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for predicting failure of a storage system based on intermittent contact between an element and a surface, said system including:
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first means for supporting said element over said surface; second means for moving said surface relative to said element, said second means including a motor; third means for detecting a change in a lateral force applied to said element during said intermittent contact between said element and said surface, wherein said lateral force comprises a frictional force and a windage force, said third means including means for detecting a change in speed of said surface during said intermittent contact of said element therewith, means for calculating said windage force, and means for providing a signal in response thereto, and fourth means for processing said signal and predicting a failure of the storage unit in response thereto. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for predicting failure of a system having a surface and an element supported over said surface, said surface being rotated relative to said element by a first motor, said method including the steps of:
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storing a torque component of a frictional force and a windage force that is applied to said element under a first state of operation of said system; measuring a torque component of a frictional force and a windage force that is applied to said element under a second state of operation of said system; and comparing the measured indication of the torque component and the windage force to the stored value to provide an indication of the state of operation of said system.
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Specification