Patent ID: 7265933

Claim:
A disk drive comprising: (a) a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors and a plurality of embedded servo sectors; (b) an actuator arm; (c) a head coupled to a distal end of the actuator arm; (d) a voice coil motor (VCM) for rotating the actuator arm about a pivot in order to actuate the head over the disk; (e) a crash stop; (f) a spin die motor for rotating the disk; and (g) control circuitry for generating a control signal applied to the VCM in response to a position error signal (PES) generated from reading the embedded servo sectors and a first feed-forward compensation value that compensates for a repeatable runout (RRO) due to a non-centric alignment of the disk with respect to the spindle motor, wherein the control circuitry computes the first feed-forward compensation value if the PES exceeds a predetermined threshold and the control circuitry computes the first feed-forward compensation value by: controlling the VCM to press the actuator arm against the crash stop; and computing the first feed-forward compensation value in response to the PES.