Patent ID: 7375916

Claim:
A method for operating a disk drive, the disk drive including (a) a rotatable magnetic recording disk having a plurality of concentric data tracks containing servo positioning information; (b) a recording head movable across the disk, the head being capable of reading data and servo positioning information in the data tracks; (c) an actuator for moving the head; (d) a disturbance sensor for sensing external disturbances to the disk drive; (e) a servo control processor responsive to a position error signal (PES) from the servo positioning information for generating an actuator control signal; and (f) a plurality of feedforward controllers, each feedforward controller generating a compensation signal to be summed with the actuator control signal for substantially canceling an external disturbance having a predefined spectrum; the processor-implemented method comprising: determining which of said plurality of predefined disturbance spectra most closely matches the actual external disturbance acting on the disk drive; selecting the feedforward controller associated with said determined predefined disturbance spectrum; and summing the compensation signal from said selected feedforward controller with the actuator control signal.