Head position control method, head position control device, and disk device

A head positioning control method for controlling positioning of a head to a predetermined position of a disk storage medium by an actuator, comprising the steps of:

• computing a position error from a target position of said head and a current position acquired from said head;
• generating state information using an estimated gain of said actuator according to an estimated position error between said position error and an estimated position of an observer, and computing a control value of said actuator from said state information;
• computing a disturbance suppression value of said actuator from state information by generating the state information using an estimated gain determination from a disturbance model defined by a transfer function of which a denominator is a numerator of a filter in which degrees of denominator and numerator for shaping a sensitivity function are the same, according to said estimated position error;
• and
• adding said control value and said disturbance suppression value, and driving said actuator,
• wherein said disturbance suppression value computing step further comprises:
• a step of generating state information using an estimated gain determined from a disturbance model of which denominator is said numerator of a linear or a quadratic filter for shaping the sensitivity function according to a desired disturbance frequency.

A head positioning control method for controlling positioning of a head to a predetermined position of a disk storage medium by an actuator, comprising the steps of:

• computing a position error from a target position of said head and a current position acquired from said head;
• generating state information using an estimated gain of said actuator according to an estimated position error between said position error and an estimated position of an observer, and computing a control value of said actuator from said state information;
• computing a disturbance suppression value of said actuator from state information by generating the state information using an estimated gain determination from a disturbance model defined by a transfer function of which a denominator is a numerator of a filter in which degrees of denominator and numerator for shaping a sensitivity function are the same, according to said estimated position error;
• and
• adding said control value and said disturbance suppression value, and driving said actuator,
• wherein said disturbance suppression value computing step further comprises the steps of:
• generating state information using an estimated gain determined from a plurality of disturbance models defined by a transfer function of which denominator is said numerator of said plurality of filters according to a plurality of disturbance frequencies to be suppressed according to said estimated position error;
• computing a plurality of disturbance suppression values of said actuator from said state information;
• and
• adding said plurality of disturbance suppression values.

A disk device, comprising:

• a head for at least reading data of a disk storage medium;
• an actuator for positioning said head at a predetermined position of said disk storage medium;
• and
• a control unit for computing a position error from a target position of said head and a current position acquired from said head, generating state information using an estimated gain of said actuator according to an estimated position error between said position error and an estimated position of an observer, and computing a control value of said actuator from said state information,
• wherein said control unit generates state information using an estimated gain determined from a disturbance model defined by a transfer function of which a denominator is a numerator of a filter in which degrees of denominator and numerator for shaping a sensitivity function are the same, according to said estimated position error, computes a disturbance suppression value of said actuator from said state information, adds said control value and said disturbance suppression value, and drives said actuator.

A head position control device for positioning a head for at least reading data of a disk storage medium to a predetermined position on said disk storage medium by controlling an actuator, comprising:

• an observer for computing an estimated position error from a target position of said head and a current position acquired from said head, generating state information using an estimated gain of said actuator according to an estimated position error between said position error and an estimated position of said observer, and computing a control value of said actuator from said state information;
• a disturbance observer for generating state information using an estimated gain determined from a disturbance model defined by a transfer function of which denominator is a numerator of a filter in which degrees of denominator and numerator for shaping a sensitivity function are the same, according to said estimated position error, and computing a disturbance suppression value of said actuator from said state information;
• and
• an addition block for adding said control value and said disturbance suppression value, and driving said actuator.