Patent classifications
G11B5/5547
SPLIT ACTUATOR DRIVE THAT LIMITS SLEW RATE OF AGGRESSOR VCM TO REDUCE VICTIM DISTURBANCES
A seek operation of a first actuator in a multi-actuator drive is modified, so that one or more disturbance-generating portions of the seek operation do not adversely affect operation of a second actuator in the drive. Radial motion of the aggressor actuator is controlled by limiting a slew rate of the first actuator during one or more portions of the seek operation to be less than or equal to a threshold value. Because slew rate of the first actuator is the rate of change of radial acceleration of the aggressor actuator with respect to time, limiting the slew rate of the first actuator prevents or reduces mechanical disturbances caused by jerk associated with motion of the first actuator.
Magnetic disk device and method of reducing microactuator voltage
According to one embodiment, when adjusting a position of a magnetic head by a microactuator, in a case where a difference of an absolute value of a first voltage value obtained by correcting a voltage value applied to the microactuator based on hysteresis and an absolute value of a second voltage value obtained by not correcting the voltage value applied to the microactuator based on the hysteresis is positive, a control unit applies a third voltage value obtained based on the second voltage value to the microactuator, and adjusts shortage of the adjustment executed by the microactuator by controlling at least one of a voice coil motor and/or a microactuator other than a microactuator applying a third voltage value.
MAGNETIC DISK DEVICE
According to one embodiment, a magnetic disk device includes a magnetic disk, a spindle motor, a magnetic head, a ramp load mechanism, a filter, and a control section. The control section rotates the spindle motor at a second rotating speed for a given period of time at startup of the device, and then loads the magnetic head from the ramp load mechanism to a prescribed position on the magnetic disk. The second rotating speed is higher than a first rotating speed at which the spindle motor is rotated at the magnetic head reads/writes data from/to the magnetic disk.
Intelligent region utilization in a data storage device
A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.
Magnetic disk device
According to one embodiment, a magnetic disk device includes a magnetic disk, a spindle motor, a magnetic head, a ramp load mechanism, a filter, and a control section. The control section rotates the spindle motor at a second rotating speed for a given period of time at startup of the device, and then loads the magnetic head from the ramp load mechanism to a prescribed position on the magnetic disk. The second rotating speed is higher than a first rotating speed at which the spindle motor is rotated at the magnetic head reads/writes data from/to the magnetic disk.
SPLIT ACTUATOR DRIVE THAT LIMITS SLEW RATE OF AGGRESSOR VCM TO REDUCE VICTIM DISTURBANCES
A seek operation of a first actuator in a multi-actuator drive is modified, so that one or more disturbance-generating portions of the seek operation do not adversely affect operation of a second actuator in the drive. Radial motion of the aggressor actuator is controlled by limiting a slew rate of the first actuator during one or more portions of the seek operation to be less than or equal to a threshold value. Because slew rate of the first actuator is the rate of change of radial acceleration of the aggressor actuator with respect to time, limiting the slew rate of the first actuator prevents or reduces mechanical disturbances caused by jerk associated with motion of the first actuator.
DISK DEVICE
According to an embodiment, in a disk device, a first actuator moves a first head with respect to a first surface of a first disk. A controller controls positioning of the first head via the first actuator and controls a write operation to the first disk by the first head. The controller acquires information regarding a state of a vibration source, changes a value of a coefficient for estimating a predicted position of the first head according to the information regarding the state of the vibration source, estimates a predicted position of the first head with the value of the coefficient changed, performs a write operation by the first head in a case where the predicted position estimated is equal to or less than a threshold, and prohibits the write operation by the first head in a case where the predicted position estimated exceeds the threshold.
Polydyne acceleration trajectory control
Various illustrative aspects are directed to a system comprising: an actuator; a control object, controlled by the actuator; and one or more processing devices, configured to perform positioning control of the control object via the actuator, wherein performing the positioning control comprises: generating a trajectory control signal for a trajectory that comprises a polydyne acceleration ramp; and outputting the trajectory control signal to the actuator.
Serpentine seeks during data storage device idle periods
Apparatus and method for managing a data storage device during extended idle conditions of the data storage device in which host access commands are not being received or serviced. In some embodiments, upon detection of an idle condition, a control circuit identifies a selected data transducer of the data storage device and a corresponding initial radial position of the data transducer with respect to an associated rotatable data recording surface. The control circuit performs a serpentine seek operation during the idle condition to gradually advance the selected data transducer in a selected radial direction across the data recording surface beginning at the initial radial position and ending at a final radial position. The serpentine seek operation prevents the transducer from being maintained in a stationary position during the idle condition, reducing the likelihood of damage through thermal asperity contact events, lubrication disturb, wear, etc.
Split-actuator disk drive that uses microactuator feedforward to reduce effects of cross-actuator coupling
In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.