Patent ID: 7535192
Filing Date: 2009-05-19
Classification: G11B

Abstract:
1. A head positioning control method for controlling positioning of a head in 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; updating estimated state information of a present sample by using said estimated state information of a present sample, an estimated gain of the actuator and estimated gain of disturbance according to an estimated position error between said position error and an estimated position of an observer by disturbance observer control including a model of said actuator and a model of disturbance; computing a control value of said actuator from said estimated state information; calculating estimated state information of both of said model of said actuator and said model of disturbance in a next sample by using said estimated state information and values of both said model of said actuator and said model of disturbance; and estimating disturbance frequency according to said estimated position error and said state information of said disturbance and changing the estimated gain of said actuator, the estimated gain of said disturbance and said values of said model of disturbance corresponding to said disturbance frequency.