Method and apparatus for spindle motor control
First Claim
Patent Images
1. A method of spindle motor control, comprising:
- (A) receiving a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding;
(B) receiving a second signal indicative of a BEMF induced in a second different stator winding;
(C) determining a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal;
(D) determining an error amount based on the speed-related characteristic;
(E) determining a correction factor for the speed-related characteristic based on the error amount; and
(F) controlling a speed of the spindle motor using the correction factor.
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Accused Products
Abstract
Information indicative of the placement of spindle motor components may be obtained and used to provide a correction to one or more BEMF-derived attributes used to control the spindle speed. In some implementations, first and second signals indicative of BEMF of different stator windings may be used to determine a speed-related characteristic. The speed related characteristic may be used to determine an error amount, which may be used to determine a correction factor to control the speed of the spindle motor.
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Citations
47 Claims
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1. A method of spindle motor control, comprising:
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(A) receiving a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding; (B) receiving a second signal indicative of a BEMF induced in a second different stator winding; (C) determining a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal; (D) determining an error amount based on the speed-related characteristic; (E) determining a correction factor for the speed-related characteristic based on the error amount; and (F) controlling a speed of the spindle motor using the correction factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A computer program operable to cause one or more machines to perform operations comprising:
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(A) receiving a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding; (B) receiving a second signal indicative of a BEMF induced in a second different stator winding; (C) determining a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal; (D) determining an error amount based on the speed-related characteristic; (E) determining a correction factor for the speed-related characteristic based on the error amount; and (F) controlling a speed of the spindle motor using the correction factor. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A spindle motor controller, comprising:
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one or more inputs configured to receive signals from a spindle motor, the signals including a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding and a second signal indicative of a BEMF induced in a second different stator winding; and a processor configured to; determine a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal; determine an error amount based on the speed-related characteristic; determine a correction factor for the speed-related characteristic based on the error amount; and generate an output signal using the correction factor, the output signal to control the speed of the spindle motor. - View Dependent Claims (32, 33, 34)
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35. A spindle motor controller, comprising:
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input means for receiving signals from a spindle motor, the signals including a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding and a second signal indicative of a BEMF induced in a second different stator winding; means for determining a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal; means for determining an error amount based on the speed-related characteristic; means for determining a correction factor for the speed-related characteristic based on the error amount; and means for generating an output signal using the correction factor, the output signal for controlling the speed of the spindle motor. - View Dependent Claims (36, 37, 38)
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39. A disc drive, comprising:
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a disc having a storage surface; a spindle motor in communication with the disc; and a spindle motor controller to control the spindle motor to rotate the disc, the spindle motor controller including; one or more inputs configured to receive signals from a spindle motor, the signals including a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding and a second signal indicative of a BEMF induced in a second stator winding; and a processor to determine a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal, the processor to further determine an error amount based on the speed-related characteristic, the processor further to determine a correction factor for the speed-related characteristic based on the error amount. - View Dependent Claims (40, 41, 42)
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43. A disc drive, comprising:
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disc means for storing data, the disc means having a storage surface; means for rotating the disc means in communication with the disc means; and means for controlling the means for rotating, the means for controlling including; input means for receiving signals from a spindle motor, the signals including a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding and a second signal indicative of a BEMF induced in a second different stator winding; means for determining a speed-related characteristic associated with motor asymmetry based on at least one of the first signal and the second signal; means for determining an error amount based on the speed-related characteristic; means for determining a correction factor for the speed-related characteristic based on the error amount; and means for generating an output signal using the correction factor, the output signal for controlling the speed of the spindle motor. - View Dependent Claims (44, 45, 46)
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47. A method of spindle motor control, comprising
receiving a first signal indicative of a back electromotive force (BEMF) induced in a first stator winding; -
receiving a second signal indicative of a back electromotive force (BEMF) induced in a second stator winding; obtaining information related to the placement of one or more motor components; and controlling a speed of the spindle motor using at least one of the first signal and the second signal and the placement information, wherein controlling the speed includes correcting for asymmetry.
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Specification