Adaptive seek control for maximum performance with minimal filter corruption
AssigneeSeagate Technology LLC
InventorsChris Thomas Settje, Frank William Bernett
Life of this patent
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Abstract
By dynamically adjusting the maximum voice coil motor driving current produced by an amplifier in a disc drive, amplifier saturation may be reduced, while still maintaining optimal current to quickly drive the voice coil motor during seek operations. Reducing disc drive saturation, and thus non-linearities in the driving current, increases notch filter performance. As the notch filter is used in the disc drive to remove frequencies from the driving current that tend to cause or excite the mechanical oscillations in the disc drive, increased notch filter performance reduces mechanical oscillations and improves disc drive noise characteristics.
Claims27
A method for optimizing seek operations in a disc drive having an amplifier for supplying a driving current to drive a voice coil motor, the driving current supplied to the voice coil motor being limited to a maximum driving current, the method comprising steps of:
- (a) determining whether the amplifier saturated during a portion of a seek operation;
- and
- (b) if the amplifier saturated during the portion of the seek operation, decreasing the maximum driving current.
A method for adaptive seek control in a disc drive having an amplifier for supplying a maximum driving current to drive a voice coil motor, the driving current supplied to the voice coil motor being limited to a maximum driving current, the method comprising steps of:
- (a) detecting a servo sample;
- (b) determining, upon detection of the servo sample, whether a seek operation is being performed;
- (c) if a seek operation is being performed, determining whether the length of the seek operation being performed is longer than a predetermined minimum seek length;
- (d) if it is determined that the length of the seek operation being performed is longer than the predetermined minimum seek length, determining whether the amplifier saturated during the portion of the seek operation;
- and
- (e) if it is determined that the amplifier saturated during the portion of the seek operation, decreasing the maximum driving current.
A system for optimizing notch filter operation in a disc drive by limiting amplifier saturation, comprising;
- a disc drive having a voice coil motor, an amplifier for supplying a maximum driving current to drive the voice coil motor, the driving current supplied to the voice coil motor being limited to a predetermined maximum driving current, and a notch filter for modifying a frequency response of the drive current;
- and
- a driving current adjustment means for dynamically defining during drive operation the maximum driving current so as to limit the amount of time the amplifier is saturated.
Dependencies are inferred from the claim text.