Method and apparatus for eliminating external disturbances in a disk drive device

A disk storage device comprising:

• a head for reading a servo signal recorded on a disk for representing a radial position and a circumferential position of said disk;
• a position detector for generating a position signal representing the position of said head based on the servo signal;
• a drive circuit for outputting a drive signal for driving an actuator having said head secured thereto in accordance with an input signal;
• a positioning compensator for calculating a positioning compensation signal to cause the position signal to coincide with a target position and outputting the positioning compensation signal to said drive circuit;
• first correction means for adding a first external disturbance compensation signal for cancelling periodic external disturbance applied to a positioning control system of said head to an input signal to said drive circuit for correction;
• memory means for storing the first external disturbance compensation signal and outputting the same in accordance with the position signal;
• second correction means for adding a second external disturbance compensation signal for cancelling the external disturbance remaining after the cancellation by the first external disturbance compensation signal to the positioning compensation signal for correction;
• estimation means for estimating the second external disturbance compensation signal as a function of the output of the second correction means and the position signal;
• and
• an external disturbance compensation signal modifier for generating a sum signal of the first external disturbance compensation signal and the second external disturbance compensation signal and storing the sum signal in said memory means as a new first external disturbance compensation signal.

A disk storage device comprising:

• a plurality of disks to be rotatably driven;
• a head for reading a servo signal recorded on said disk to represent a radial position and a circumferential position on said disk;
• a position detector for generating a position signal representing the position of said head based on the servo signal;
• an actuator having said head secured thereto;
• a drive circuit for outputting a drive signal for driving said actuator in accordance with an input signal;
• a head positioning servo mechanism including a positioning compensator for calculating a positioning compensation signal such that the position signal coincides to a target position and outputting the same to said drive circuit;
• a controller for controlling said servo mechanism;
• first correction means for adding a first external disturbance compensation signal for cancelling periodic external disturbance applied to said head positioning control system for correction;
• memory means for storing the first external disturbance compensation signal and outputting the same in accordance with the position signal;
• second correction means for adding a second external disturbance compensation signal for cancelling the external disturbance remaining after the cancellation by the first external disturbance compensation signal to the positioning compensation signal for correction;
• estimation means for estimating the second external disturbance compensation signal as a function of the output of said second correction means and the position signal and;
• an external disturbance compensation signal modifier for generating a sum of the first external disturbance compensation signal and the second external disturbance compensation signal and storing the same in said memory means as a new first external disturbance compensation signal;
• said external disturbance compensation signal modifier updating the first external disturbance compensation signal stored in said memory means when said head is positioned to a predetermined track;
• and
• said first correction means correcting by using the updated first external disturbance compensation signal.

A disk storage device comprising:

• a plurality of disks to be rotatably driven;
• a head for reading a servo signal recorded on said disk to represent a radial position and a circumferential position on said disk;
• a position detector for generating a position signal representing the position of said head based on the servo signal;
• an actuator having said head secured thereto;
• a drive circuit for outputting a drive signal for driving said actuator in accordance with an input signal;
• a head positioning servo mechanism including a positioning compensator for calculating a positioning compensation signal such that the position signal coincides to a target position and outputting the same to said drive circuit;
• a controller for controlling said servo mechanism;
• first correction means for adding a first external disturbance compensation signal for cancelling periodic external disturbance applied to said head positioning control system for correction;
• memory means for storing the first external disturbance compensation signal and outputting the same in accordance with the position signal;
• second correction means for adding a second external disturbance compensation signal for cancelling the external disturbance remaining after the cancellation by the first external disturbance compensation signal to the positioning compensation signal for correction;
• estimation means for estimating the second external disturbance compensation signal as a function of the output of said second correction means and the position signal;
• an external disturbance compensation signal modifier for generating a sum of the first external disturbance compensation signal and the second external disturbance compensation signal and storing the same in said memory means as a new first external disturbance compensation signal;
• said external disturbance compensation signal modifier updating the first external disturbance compensation signal stored in said memory means when said head is positioned to a predetermined track;
• said first correction means correcting by using the updated first external disturbance compensation signal and said second correction means correcting by using the second external disturbance compensation signal.

A disk storage device comprising:

• a plurality of disks to be rotatably driven;
• a head for reading a servo signal recorded on said disk to represent a radial position and a circumferential position on said disk;
• a position detector for generating a position signal representing the position of said head based on the servo signal;
• an actuator having said head secured thereto;
• a drive circuit for outputting a drive signal for driving said actuator in accordance with an input signal;
• a head positioning servo mechanism including velocity signal estimation means for estimating a velocity signal of said head as a function of the drive signal and the position signal and a positioning compensator for calculating a positioning compensation signal such that the position signal coincides to a target position and outputting the same to said drive circuit;
• a controller for controlling said servo mechanism;
• first correction means for adding a first external disturbance compensation signal for cancelling periodic external disturbance applied to said head positioning control system for correction;
• memory means for storing the first external disturbance compensation signal and outputting the same in accordance with the position signal;
• second correction means for adding a second external disturbance compensation signal for cancelling the external disturbance remaining after the cancellation by the first external disturbance compensation signal to the positioning compensation signal for correction;
• estimation means for estimating the second external disturbance compensation signal as a function of the output of said second correction means and the position signal;
• an external disturbance compensation signal modifier for generating a sum of the first external disturbance compensation signal and the second external disturbance compensation signal and storing the same in said memory means as a new first external disturbance compensation signal;
• and
• third correction means for subtracting the new first external disturbance compensation signal form the drive signal for correction;
• said external disturbance compensation signal modifier updating the first external disturbance compensation signal stored in said memory means when said head is positioned to a predetermined track;
• said first correction means correcting by using the updated first external disturbance compensation signal and the output signal of said third correction means being applied to said velocity signal estimation means instead of the drive signal.

A disk storage device comprising:

• a plurality of disks to be rotatably driven;
• a head for reading a servo signal recorded on said disk to represent a radial position and a circumferential position on said disk;
• a position detector for generating a position signal representing the position of said head based on the servo signal;
• an actuator having said head secured thereto;
• a drive circuit for outputting a drive signal for driving said actuator in accordance with an input signal;
• a head positioning servo mechanism including velocity signal estimation means for estimating a velocity signal of said head as a function of the drive signal and the position signal and a positioning compensator for calculating a positioning compensation signal such that the position signal coincides to a target position and outputting the same to said drive circuit;
• a controller for controlling said servo mechanism;
• first correction means for adding a first external disturbance compensation signal for cancelling periodic external disturbance applied to said head positioning control system for correction;
• memory means for storing the first external disturbance compensation signal and outputting the same in accordance with the position signal;
• second correction means for adding a second external disturbance compensation signal for cancelling the external disturbance remaining after the cancellation by the first external disturbance compensation signal to the positioning compensation signal for correction;
• estimation means for estimating the second external disturbance compensation signal as a function of the output of said second correction means and the position signal;
• an external disturbance compensation signal modifier for generating a sum of the first external disturbance compensation signal and the second external disturbance compensation signal and storing the same in said memory means as a new first external disturbance compensation signal;
• and
• third correction means for subtracting the new first external disturbance compensation signal form the drive signal for correction;
• said external disturbance compensation signal modifier updating the first external disturbance compensation signal stored in said memory means when said head is positioned to a predetermined track;
• said first correction means correcting by using the updated first external disturbance compensation signal and said second correction means correcting by using the second external disturbance compensation signal, and the output signal of said third correction means being applied to said velocity signal estimation means instead of the drive signal.