Head position control method, head position control device, and disk device
AssigneeFujitsu Limited
InventorKazuhiko Takaishi
Life of this patent
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Abstract
A position control device corrects the displacement of the head by disturbance applied to the disk device by the control system. An adaptive control to an unknown disturbance frequency is performed. The frequency estimation block for estimating the external vibration frequency from a signal that is based on the position error according to the adaptive rule, and a correction table for sequentially correcting the constants of the compensator using this external vibration frequency, are provided. Since the constants of the compensator are sequentially corrected according to the estimated angular frequency, highly accurate follow up control to an external vibration frequency in a wide range becomes possible.
Claims27
A head positioning control method for controlling positioning of a head onto a desired track of a disk by an actuator according to a position signal which the head has read from the disk, comprising the steps of:
- calculating a control value of the actuator according to a position error between a target position and a current position acquired from said position signal;
- estimating sequentially external vibration frequency from a signal that is based on the position error according to an adaptive rule;
- estimating a rotation vector of cyclic disturbance from the signal that is based on the position error and calculating an external vibration suppression control value using a constant for external vibration suppression,
- sequentially correcting said constant for external vibration suppression according to each of the sequentially estimated external vibration frequencies;
- and
- generating a drive value of the actuator by adding the control value and the external vibration suppression control value.
A head positioning control device for controlling the positioning of a head onto a desired track of a disk by an actuator according to a position signal which the head has read from the disk, comprising:
- a control block for obtaining a control value of the actuator according to a position error between a target position and a current position acquired from the position signal;
- an adaptive control block for estimating sequentially external vibration frequency from a signal that is based on the position error according to an adaptive rule, estimating a rotation vector of cyclic disturbance from the signal based on the position error, obtaining an external vibration suppression control value using a constant for external vibration suppression, and sequentially correcting the constant for external vibration suppression according to each of the sequentially estimated external vibration frequencies;
- and
- an addition block for adding the control value and the external vibration suppression control value and generating a drive value of the actuator.
A disk device, comprising:
- a head for reading information from a disk;
- an actuator for moving the head in the track crossing direction of the disk;
- and
- a control unit for obtaining a control value of the actuator according to a position error between a target position and a current position acquired by a position signal read by the head so as to position the head onto a desired track of a disk according to the position signal,
- wherein said control section further comprises:
- an adaptive control block for estimating sequential external vibration frequencies from the signal that is based on the position error according to an adaptive rule, estimating a rotation vector of cyclic disturbance from the signal that is based on the position error, obtaining an external vibration suppression control value using a constant for external vibration suppression, and sequentially correcting the constant for external vibration suppression according to each of the sequentially estimated external vibration frequencies;
- and
- an addition block for adding the control value and the external vibration suppression control value and generating a drive value of the actuator.
Dependencies are inferred from the claim text.