An apparatus and method for compensating actuator arm oscillation induced by
resonance
mode excitation during a seek in a disc drive data handling system. The actuator
arm supports a head adjacent a recording surface, and a servo loop controls the
position of the actuator arm. A frequency of actuator arm oscillation is identified,
after which a seek is initiated to move the head from an initial track to a destination
track on the recording surface. A position error signal (PES) is generated to indicate
position of the head relative to the destination track, and a compensation signal
is generated by a filter based on the PES and the frequency of oscillation of the
actuator arm. The compensation signal is adapted to remove a component of the PES
arising from the actuator arm oscillation, and is applied to the servo loop as
the head is settled onto the destination track.