Method and apparatus for head positioning control in disk drive
AssigneeKabushiki Kaisha Toshiba
InventorMasafumi Iwashiro
Life of this patent
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Abstract
A servo system is disclosed which is applied to a disk drive for detecting characteristic frequency components of a position error between a position of the head and the target position, and calculating a control correction value for correcting a control value. The servo system estimates the frequency components of target value variation from the characteristic frequency components of the position error, thereby modifying the characteristic frequency components to follow the target value variation. Thus, the servo system calculates the control correction value for suppressing the target value variation, and executes head positioning control, using a value obtained by adding the control value to the control correction value.
Claims10
A positioning control system situating a head in a target position on a disk incorporated in a disk drive, comprising:
- a position error detector detecting a position error between a position of the head and the target position;
- a frequency detector that detecting a characteristic frequency component included in the position error, using a Fourier transform;
- an estimator estimating a frequency of a disturbance, related to a target value variation, on the basis of a Fourier coefficient resulting from the Fourier transform;
- and
- a controller modifying the characteristic frequency component on the basis of the frequency of the disturbance estimated by the estimator, and calculating a control correction value for suppressing the target value variation having the modified characteristic frequency component.
A head positioning control method for use in a disk drive, comprising:
- detecting a position error between a position of the head and the target position;
- detecting a characteristic frequency component included in the position error, using a Fourier transform;
- estimating a frequency of a disturbance, related to a target value variation, on the basis of a Fourier coefficient resulting from the Fourier transform;
- modifying the characteristic frequency component on the basis of the estimated frequency of the disturbance;
- and
- calculating a control correction value that suppresses the target value variation having the modified characteristic frequency component.
A servo system that situates a plant in a target position, comprising:
- a position error detector detecting a position error between a position of the plant and the target position;
- a frequency detector detecting a characteristic frequency component included in the position error, using a Fourier transform;
- an estimator estimating a frequency of a disturbance, related to a target value variation, on the basis of a Fourier coefficient resulting from the Fourier transform;
- and
- a controller modifying the characteristic frequency component on the basis of the frequency of the disturbance estimated by the estimator, calculates a control correction value for suppressing the target value variation having the modified characteristic frequency component, and executes positioning control using a value obtained by adding the control correction value to a control value for correcting the position error.
Dependencies are inferred from the claim text.