Patent ID: 6891693

Claim:
A system for head positioning control that includes seek control, used to move a head to a target position on a disk, and track following control, used to position the head in a target area related to the target position, comprising: means for detecting a position error between a position of the head and the target position; means for calculating, from the position error, a feedback value used to eliminate the position error; adaptive learning means for acquiring, by adaptive learning, a runout component that is included in the position error and synchronous with a rotation of the disk; means for calculating a feedforward value used to suppress the runout component acquired by the adaptive learning means; means for generating, from the feedback value and the feedforward value, a control amount used to position the head in the target position; a rewritable memory to store initial values used in adaptive learning executed by the adaptive learning means, the initial values being values of the runout component obtained in respective predetermined radial positions on the disk; and determination means for selecting, from the memory, one of the initial values, used in adaptive learning by the adaptive learning means, in accordance with the target position, and supplying the selected initial value to the adaptive learning means.