| 摘要 |
In a disk drive, servo gain correction, in the presence of servo code signal variations, is achieved by utilizing the servo position signals to produce a servo gain scaling signal which is combined with the servo position signals to produce a corrected servo position signal for controlling the servo. The disk tracks comprise four phases of servo code, either dedicated or sampled servo code. The servo code is conventionally defined by four phases of recorded magnetic dibits, A, B, C, D. Normal, N, [N=(A-B)] and quadrature, Q, [Q=(C-D)], servo position signals are developed from the recorded dibits, either or both of the normal and quadrature signals may be used for controlling the servo. Absolute value signals N and Q are rectified values of the normal N, and quadrature, Q, signals. The absolute value signals are summed to produce a scaling signal, N + Q , and the respective servo signals N and Q are scaled by multiplication with an inverse function <IMAGE> of the scaling signal, N + Q , called the servo gain scaling signal, to produce a corrected servo position signal, N*, or, Q*, respectively defined as <IMAGE> either of which, or the joint use of which, may be employed for controlling the servo system.
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