Data storage device concurrently controlling and sensing a secondary actuator for actuating a head over a disk
AssigneeWestern Digital Technologies, Inc.
InventorsTimothy A. Ferris, Jaesoo Byoun
Life of this patent
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Abstract
A data storage device is disclosed comprising a voice coil motor (VCM) and a secondary actuator configured to actuate a head over a disk. A control signal is applied to the secondary actuator while processing a sensor signal generated by the secondary actuator. A vibration signal is generated based on the sensor signal, wherein the vibration signal is a high-pass signal.
Claims39
A data storage device comprising:
- a disk;
- a head;
- a voice coil motor (VCM) and a secondary actuator configured to actuate the head over the disk;
- a sensor capacitor proportional to a capacitance of the secondary actuator;
- and
- control circuitry configured to:
- apply a control signal to the secondary actuator and concurrently process a sensor signal generated by the secondary actuator;
- and
- generate a vibration signal based on the sensor signal and the sensor capacitor, wherein a capacitance of the sensor capacitor is at least two times less than a capacitance of the secondary actuator.
A data storage device comprising:
- a disk;
- a head;
- a voice coil motor (VCM) and a secondary actuator configured to actuate the head over the disk;
- and
- control circuitry configured to:
- measure a position of the head over the disk;
- generate a control signal based on the measured position of the head;
- apply the control signal to the secondary actuator;
- process a sensor signal generated by the secondary actuator;
- generate a sensor current proportional to a current applied to the secondary actuator due to the control signal;
- estimate a capacitive voltage of the secondary actuator by applying the sensor current to a sensor capacitor that is proportional to a capacitance of the secondary actuator;
- generate a vibration signal based on a difference between the sensor signal and the estimated capacitive voltage;
- and
- adapt a gain of the sensor capacitor based on the control signal and the estimated capacitive voltage.
A method of operating a data storage device, the method comprising:
- actuating a head over a disk using a voice coil motor (VCM) and a secondary actuator;
- applying a control signal to the secondary actuator and concurrently process a sensor signal generated by the secondary actuator;
- and
- generating a vibration signal based on the sensor signal, wherein the vibration signal has a cut-off frequency between ten percent and ninety percent of a bandwidth of a control loop for controlling the secondary actuator.
A method of operating a data storage device, the method comprising:
- actuating a head over a disk using a voice coil motor (VCM) and a secondary actuator;
- measuring a position of the head over the disk;
- generating a control signal based on the measured position of the head;
- applying the control signal to a secondary actuator configured to actuate the head over the disk;
- processing a sensor signal generated by the secondary actuator;
- generating a sensor current proportional to a current applied to the secondary actuator due to the control signal;
- estimating a capacitive voltage of the secondary actuator by applying the sensor current to a sensor capacitor that is proportional to a capacitance of the secondary actuator;
- generating a vibration signal based on a difference between the sensor signal and the estimated capacitive voltage;
- and
- adapting a gain of the sensor capacitor based on the control signal and the estimated capacitive voltage.
Control circuitry configured to control a voice coil motor (VCM) and a secondary actuator to actuate a head over a disk, the control circuitry configured to:
- apply a control signal to the secondary actuator and concurrently process a sensor signal generated by the secondary actuator;
- and
- generate a vibration signal based on the sensor signal, wherein the vibration signal has a cut-off frequency between ten percent and ninety percent of a bandwidth of a control loop for controlling the secondary actuator.
Control circuitry configured to control a voice coil motor (VCM) and a secondary actuator to actuate a head over a disk, the control circuitry configured to:
- measure a position of the head over the disk;
- generate a control signal based on the measured position of the head;
- apply the control signal to the secondary actuator;
- process a sensor signal generated by the secondary actuator;
- generate a sensor current proportional to a current applied to the secondary actuator due to the control signal;
- estimate a capacitive voltage of the secondary actuator by applying the sensor current to a sensor capacitor that is proportional to a capacitance of the secondary actuator;
- generate a vibration signal based on a difference between the sensor signal and the estimated capacitive voltage;
- and
- adapt a gain of the sensor capacitor based on the control signal and the estimated capacitive voltage.
Dependencies are inferred from the claim text.