Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk, and a second actuator configured to actuate a second head over a second disk. The first actuator is controlled based on a first feed-forward seek profile to seek the first head over the first disk, and the second actuator is controlled to position the second head over a second data track on the second disk including to process the first feed-forward seek profile to attenuate a coupling disturbance from the first actuator.

Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

An apparatus includes voice coil motor (VCM) control circuitry and microactuator control circuitry. The VCM control circuitry includes a VCM disturbance observer configured to generate a VCM disturbance compensation signal. The microactuator control circuitry includes a microactuator disturbance observer configured to generate a microactuator disturbance compensation signal. The VCM disturbance observer and the microactuator disturbance observer are decoupled from each other.

An apparatus includes voice coil motor (VCM) control circuitry and microactuator control circuitry. The VCM control circuitry includes a VCM disturbance observer configured to generate a VCM disturbance compensation signal. The microactuator control circuitry includes a microactuator disturbance observer configured to generate a microactuator disturbance compensation signal. The VCM disturbance observer and the microactuator disturbance observer are decoupled from each other.

Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

According to an embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, and a control circuit. The magnetic disk has a plurality of first storage regions disposed in the radial direction. The recording method is changeable for each of the plurality of first storage regions. The control circuit operates such that, when having received a first command instructing to change the recording method of one first storage region out of a plurality of first storage regions, the control circuit changes the recording method of the one first storage region in accordance with the first command, and moves a magnetic head onto the second storage region before receiving a second command.

A data storage device may include one or more disks; a voice coil motor (VCM) driver for driving a VCM and having a programmable transconductance (G.sub.m); an actuator arm assembly comprising one or more disk heads and the VCM, wherein the VCM is configured to operate in a first mode and a second mode; and one or more processing devices configured to control the actuator arm assembly to actuate the disk heads over corresponding disk surfaces of the disks, and further configured to: determine a current mode of operation of the VCM, the current mode of operation comprising the first mode; and transition the VCM from the current mode of operation to a new mode of operation, the new mode of operation comprising the second mode, wherein the transitioning comprises tuning the G.sub.m from a first transconductance value to a second, different transconductance value.

A data storage device includes a disk, a head, a microactuator, a coarse actuator, and a servo controller. The microactuator is configured to position the head relative to the disk. The coarse actuator is configured to position the microactuator relative to the disk. The servo controller is configured to generate an adjusted position error signal based on a position error signal and an estimated microactuator position signal. The servo controller is also configured to filter the adjusted position error signal with a shaping filter to generate a filtered position error signal, and to provide sliding mode control of the coarse actuator based at least partially on the filtered position error signal.

A data storage device includes a disk, a head, a microactuator, a coarse actuator, and a servo controller. The microactuator is configured to position the head relative to the disk. The coarse actuator is configured to position the microactuator relative to the disk. The servo controller is configured to generate an adjusted position error signal based on a position error signal and an estimated microactuator position signal. The servo controller is also configured to filter the adjusted position error signal with a shaping filter to generate a filtered position error signal, and to provide sliding mode control of the coarse actuator based at least partially on the filtered position error signal.