Seagate Technology Incorporated

University of Illinois

Evgeny R Kharisov

Raye Abdoulie Sosseh

Josiah Natan Wernow

Mark A Gaertner

Kenneth A Haapala

Binh Kim Lieu

Qiang Bi

John Christopher Morris

Lealon Ray McKenzie

Richard P Michel

Vidur Parkash

Zai Yu Nang

Seow Zhao Li

A method includes generating a first feedforward signal based, at least in part, on a sensor signal. The method further includes generating a second feedforward signal based, at least in part, on a feedforward seek table. A control signal is modified based, at least in part, on the first feedforward signal and the second feedforward signal. A position of an actuator is controlled in response to the modified control signal.

Seek-induced vibration compensation

A method includes determining at least one of an areal density margin or a reliability margin for a combination of a head and a data storage surface in a data storage drive. The method also includes employing the determined at least one of the AD margin or the reliability margin to adjust an on-cylinder limit value associated with the combination of the head and the data storage surface.

Vibration-induced on-cylinder limit adjustment

A data storage system can be vigilant of the acoustic impedance between cooling features and a data storage device to prevent operational degradation in the data storage device as a result of cooling operations from the cooling features. One or more cooling feature may each be positioned on an opposite sides of an air plenum from a data storage device with each cooling feature connected to a cooling module configured to adjust a speed of the first cooling feature in response to a detected operational condition in the data storage device. The cooling features speed adjustment is executed independently to correct an acoustic and vibration disturbance interference in the data storage system.

Acoustic and vibration mitigation in a data storage system

A data storage device includes a first data storage surface and a second data storage below the first data storage surface. The data storage device also includes a first micro-actuator coupled to a first arm that supports a first head over the first data storage surface, and a second micro-actuator coupled to a second arm that supports a second head over the second data storage surface. The data storage device further includes a coarse actuator, to which the first and second arms are coupled, that positions the first head and the second head between corresponding first and second tracks on the respective first and second data storage surfaces. Micro-actuator drive circuitry finely positions the first head over the first track and the second head over the second track by concurrently driving the first micro-actuator and the second micro-actuator in opposite directions.

Parallel servo control in a data storage device

A faulty tracking condition affecting a first head driven by a first actuator of a hard disk drive is determined. The faulty tracking condition is caused by a second actuator of the hard disk drive that is moving while the first actuator is performing a tracking operation. Responsive to the determination of the faulty tracking condition, seek forces of the second actuator that cause the faulty tracking condition affecting the first head are reduced. A controller verifies that similar faulty tracking conditions are reduced with the first head in response to the reduction in seek forces.

Method and apparatus that modifies seek parameter to remediate cross-actuator interference

Method and apparatus that modifies seeks to remediate inter-actuator coupling in a storage drive

In a disk drive apparatus, a first time period is determined, during which a first head driven by a first actuator will be performing a first disk access operation. A second time period is determined, during which a second head driven by a second actuator will be performing a second disk access operation. The first and second actuators are independently movable such that the first and second disk access operations are capable of being performed in parallel. If it is determined that the second disk access operation will impact servo control of the first disk access operation, at least one of the first and second disk access operations is changed to reduce the impact to the servo control of the first disk access operation.

Changing disk access operations to reduce servo control impact in a multiple actuator drive

An apparatus includes a first controller, a second controller, and a coupling compensator. The first controller is configured to generate a first voice coil motor (VCM) control signal in response to a first position error signal. The second controller is configured to generate a second VCM control signal in response to a second position error signal. The coupling compensator is configured to generate a first feedforward correction signal in response to the first VCM control signal. The first feedforward correction signal modifies the second VCM control signal to generate a modified second VCM control signal.

Feedforward compensation for multi-actuator hard drives

Certain exemplary aspects of the present disclosure are directed towards apparatuses and methods which mitigate the effect of speaker vibration on a disc drive. Audio associated with a speaker output is detected and triggers the generation of an output signal indicative of speaker vibration associated with such an audio output of a speaker. A magnetoresistive transducer of the disc drive is positioned relative to a storage medium based on the output signal, a target data storage location in the storage medium from which data is to be accessed via the positioning, and the position of the transducer. The output signal mitigates the effect of the speaker vibration on the transducer.

Disc drive speaker vibration mitigation

An apparatus includes a first read/write head coupled to a first micro actuator, a second read/write head coupled to a second micro actuator, an actuator and a controller. The actuator is coupled to both the first and second micro actuators. The controller is configured to position the first read/write head in response to a first micro actuator control signal and an actuator control signal. Further, the controller is configured to position the second read/write head in response to a second micro actuator control signal and the actuator control signal. The positioning of the first and second read/write heads by the controller is performed substantially simultaneously.

Disk drive with parallel head actuation

First and second position error signals (PES) are measured from respective first and second read heads that are simultaneously reading two different surfaces of a recording medium. A common repeatable runout (RRO) compensation signal and a differential RRO signal are determined based on the first and second PES. A voice coil motor that drives the first and second read heads is adjusted using the common RRO compensation signal, and first and second microactuators that respectively position the first and second read heads are adjusted based on the differential RRO signal.

Multiple head control using common and differential position error signals

An apparatus includes a feedback controller receiving feedback from a position error signal of a hard drive read/write head. The feedback controller provides respective voice coil motor and microactuator control signals to a voice coil and microactuator that together position the hard drive read/write head in response to a position control signal. A rotational vibration feed-forward compensator receives vibration measurements via a sensor and providing a rotational vibration compensation signal in response thereto. A dynamic control allocator is coupled to the feedback controller and the rotational vibration feed-forward compensator. The dynamic control allocator is configured to combine a high frequency component of the rotational vibration compensation signal with the microactuator control signal; and to combine a low frequency component of the rotational vibration compensation signal with the voice coil motor control signal.

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Brooklyn, NY, United States of America

Evgeny R Kharisov