Abstract: A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors recorded around the circumference of the disk at a servo sampling frequency, and a servo control system operable to actuate a head over the disk by generating a control signal applied to an actuator. A first sinusoid is injected into the servo control system and a first DC component (dc1) is measured in the control signal. A second sinusoid is injected into the servo control system and a second DC component (dc2) is measured in the control signal, wherein the second sinusoid comprises a phase offset from the first sinusoid. A resonance mode of the servo control system is measured based on dc1 and dc2.

Abstract: A data storage device adapted to compensate for physical disturbances has a storage medium, a read-write mechanism positionable relative to the storage medium, and a disturbance observer. The read-write mechanism is adapted to read and write data. The disturbance observer compensates a position of the read-write mechanism according to low-frequency components of physical disturbances.

Abstract: A voltage-mode VCM controller is provided comprising an Infinite Impulse Response (IIR) filter that modifies a servo control voltage signal to a voltage driver in response to an adaptive compensator that configures the IIR filter in relation to an observed VCM velocity and an actual VCM velocity. An associated method is provided comprising modeling a velocity response of a VCM to a voltage input; inputting the observed velocity and an actual VCM velocity to an adaptive compensator that computes a gain and a VCM response pole frequency in relation to the VCM resistance and inductance; configuring an IIR filter in relation to the computed gain and pole frequency values; and using the IIR filter to modify a voltage command from a servo controller to a power driver.

Abstract: A data storage device adapted to compensate for physical disturbances has a storage medium, a read-write mechanism positionable relative to the storage medium, and a disturbance observer. The read-write mechanism is adapted to read and write data. The disturbance observer compensates a position of the read-write mechanism according to low-frequency components of physical disturbances.

Abstract: A voltage-mode VCM controller is provided comprising an Infinite Impulse Response (IIR) filter that modifies a servo control voltage signal to a voltage driver in response to an adaptive compensator that configures the IIR filter in relation to an observed VCM velocity and an actual VCM velocity. An associated method is provided comprising modeling a velocity response of a VCM to a voltage input; inputting the observed velocity and an actual VCM velocity to an adaptive compensator that computes a gain and a VCM response pole frequency in relation to the VCM resistance and inductance; configuring an IIR filter in relation to the computed gain and pole frequency values; and using the IIR filter to modify a voltage command from a servo controller to a power driver.