Patent ID: 6937423

Claim:
In a disk drive comprising a base, a cover, a disk being formatted with embedded servo sectors, a rotary actuator, a head affixed to the rotary actuator for reading the servo sectors, a sensor mounted for detecting acceleration of the disk drive, and a sampled servo control system for processing the detected acceleration and the servo sectors read by the head to control motion of the rotary actuator, a method for reducing the effects of rotational vibration in the disk drive, the method comprising: sensing vibration by the sensor and generating a corresponding sensor data; deriving a statistical sensor (SS) value based on the sensor data; deriving a statistical position error signal (SPES) value from the servo sectors read by the head; comparing the SS value to a SS-threshold value; comparing the SPES value to a SPES-threshold value; and generating a feed-forward command effort signal for reducing the effects of rotational vibration if the SS value exceeds the SS-threshold value and if the SPES value exceeds the SPES-threshold value.