Abstract: A head unit device for controlling motion of an object includes a chamber filled with a shear thickening fluid (STF) and a piston. The piston is housed within the chamber and exerts pressure against the STF from a force applied to the piston from the object. The STF is configured to have a decreasing viscosity in response to a first range of shear rates and an increasing viscosity in response to a second range of shear rates. The piston includes at least one piston bypass between opposite sides of the piston that controls flow of the STF between the opposite sides of the piston to selectively react with a shear threshold effect of the first range of shear rates or the second range of shear rates.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position heads proximate to a recording medium of the disks; a spindle motor configured for rotating the one or more disks; and one or more processing devices comprising a servo control processor. The servo control processor is configured to receive a spindle speed error signal indicative of an error in a rotational speed of the spindle motor. The servo control processor is further configured to output an initial frequency offset signal, wherein the initial frequency offset signal is proportional to the spindle speed error signal.

Abstract: A data storage device comprises a disk having a plurality of data tracks and a plurality of servo wedges wherein the plurality of servo wedges comprise a plurality of wedge repeatable runout (WRRO) fields configured to store a plurality of WRRO compensation values in connection with the plurality of data tracks. The data storage device may also include a read/write head configured to be actuated over the disk, and a controller configured to gather position error signal (PES) data needed for computation of the WRRO compensation values during a field operation of the data storage device. The data storage device may be further configured to adjust a position of the read/write head based on the WRRO compensation values.

Abstract: A data storage device comprises a disk having a plurality of data tracks and a plurality of servo wedges wherein the plurality of servo wedges comprise a plurality of wedge repeatable runout (WRRO) fields configured to store a plurality of WRRO compensation values in connection with the plurality of data tracks. The data storage device may also include a read/write head configured to be actuated over the disk, and a controller configured to gather position error signal (PES) data needed for computation of the WRRO compensation values during a field operation of the data storage device. The data storage device may be further configured to adjust a position of the read/write head based on the WRRO compensation values.

Abstract: A data storage device is disclosed comprising a head actuated over a disk surface comprising a plurality of servo sectors, wherein each servo sector comprises a servo burst field. Across a first radial band of servo tracks, the servo burst field comprises a first length, and across a second radial band of servo tracks, the servo burst field comprises a second length longer than the first length. When the head is over the first radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a first servo sector and the second read element concurrently reading a second servo sector different from the first servo sector. When the head is over the second radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a third servo sector.

Abstract: A data storage device is disclosed comprising a first disk surface comprising a plurality of servo tracks, a first head actuated over the first disk surface, wherein the first head comprises a first read element, and a second read element. During a write operation first servo data in a first servo track is read using the first read element to generate a first read signal, and the first head is servoed over the first servo track based on the first read signal while writing data to the first disk surface. Second servo data is read using the second read element to generate a second read signal, and the write operation is aborted when the first read signal indicates a shock event is affecting the servoing of the first head and the second read signal confirms the shock event.

Abstract: A data storage device is disclosed comprising a first disk comprising first servo sectors A0-AN distributed around a circumference of the first disk, and a second disk comprising second servo sectors B0-BN distributed around a circumference of the second disk, wherein the second servo sectors B0-BN are offset circumferentially from the first servo sectors A0-AN. While the first and second disks are rotating second servo information is transmitted from a second servo channel to a first servo channel. One of the first servo sectors Ai is read to generate first servo information, and a first command value is generated based on the first servo information and the second servo information, wherein a first actuator is controlled based on the first command value.

Abstract: A method for repairing at least one defective servo segment of a servo sector having at least one defective servo track written on a magnetic recording media. The method comprises mapping the magnetic recording media for locations of the defective servo segment of the servo sector. A non-defective segment of the servo sector is replicated at least once on the magnetic recording media in a customer data zone, thereby creating at least one good servo segment copy of the servo sector. The good servo segment copy is propagated through the customer data zone associated with the defective servo segment. The good servo segment copy is copied onto the magnetic recording media previously occupied by the defective servo segment of the servo sector.

Abstract: A method for repairing at least one defective servo segment of a servo sector having at least one defective servo track written on a magnetic recording media. The method comprises mapping the magnetic recording media for locations of the defective servo segment of the servo sector. A non-defective segment of the servo sector is replicated at least once on the magnetic recording media in a customer data zone, thereby creating at least one good servo segment copy of the servo sector. The good servo segment copy is propagated through the customer data zone associated with the defective servo segment. The good servo segment copy is copied onto the magnetic recording media previously occupied by the defective servo segment of the servo sector.

Abstract: Magnetic disk drive systems and associated methods are described for precisely detecting contact of read/write elements of a recording head with a magnetic disk due to increasing a heating power applied to heating elements in the recording head. Contact is detected based on adjusted timing signals which are generated by measuring the current applied to a spindle motor, and generating an estimated timing signal from the measured motor current for increments of the heating power. An actual servo timing signal is simultaneously measured from servo fields on the magnetic disk, and the adjusted timing signals are calculated based on the difference between the estimated timing signal and the servo timing signal. Multivariate statistical analysis may also be performed on the adjusted timing signals and other contact indicative variables (such as off-track and slider vertical bouncing) to generate a likelihood of contact at the increments of the heating power.

Abstract: Write control bits are associated with servo pattern data bits to selectively disable or enable a write gate in a HDD write channel for self-servo writing after being sealed but before being vended to a user. The write gate can be disabled and enabled without deenergizing the write channel. A single write delay is calculated from one timing mark to the next to enable writing the next timing mark and portions of the radial pattern and servo pattern between the timing marks.

Abstract: A method and apparatus for providing combined radial and timing multislot self-servowrite propagation is disclosed. Radial bursts are combined with each timing mark and requires only three recovery/read-write spacing allocations per sector. The channel operates without requiring the writing of any bursts between reading radial bursts.

Abstract: Write control bits are associated with servo pattern data bits to selectively disable or enable a write gate in a HDD write channel for self-servo writing after being sealed but before being vended to a user. The write gate can be disabled and enabled without deenergizing the write channel. A single write delay is calculated from one timing mark to the next to enable writing the next timing mark and portions of the radial pattern and servo pattern between the timing marks.

Abstract: A method and apparatus for providing combined radial and timing multislot self-servowrite propagation is disclosed. Radial bursts are combined with each timing mark and requires only three recovery/read-write spacing allocations per sector. The channel operates without requiring the writing of any bursts between reading radial bursts.

Abstract: Write control bits are associated with servo pattern data bits to selectively disable or enable a write gate in a HDD write channel for self-servo writing after being sealed but before being vended to a user. The write gate can be disabled and enabled without deenergizing the write channel. A single write delay is calculated from one timing mark to the next to enable writing the next timing mark and portions of the radial pattern and servo pattern between the timing marks.

Abstract: Write control bits are associated with servo pattern data bits to selectively disable or enable a write gate in a HDD write channel for self-servo writing after being sealed but before being vended to a user. The write gate can be disabled and enabled without deenergizing the write channel. A single write delay is calculated from one timing mark to the next to enable writing the next timing mark and portions of the radial pattern and servo pattern between the timing marks.

Abstract: An apparatus (10) includes an inflatable vehicle occupant protection device (12), a cover (32) for the protection device (12), and a pair of clamping parts (34, 42) with a fastener structure (36, 40). The protection device (12) comprises a first compressively deflectable structure. The cover (32) comprises a second compressively deflectable structure. The fastener structure (36, 40) comprises a stud (36) extending longitudinally between the clamping parts (34, 42), and applies a clamping load to the clamping parts (34, 42). At least one of the deflectable structures (12, 32) is compressively stressed by the clamping load. The apparatus (10) further includes a bushing (48) which is indeflectable under the clamping load. The bushing (48) extends over the stud (36) fully between the clamping parts (34, 42) to space the clamping parts (34, 42) from each other. Accordingly, the spacing between the clamping parts (34, 42) is unaffected by creep in the compressively stressed deflectable structure.

Abstract: A method of digitizing an input analog current signal such as a demodulated servo position error signal in a disk file includes charging a capacitor with the input demodulated signal, and comparing the resulting capacitor voltage with a plurality of thresholds to produce a comparator output signal for each threshold exceeded by the capacitor voltage. The comparator output signals are sampled, and each sampling period a current corresponding to the thresholds exceeded is generated. The generated current is used to draw off charge from the capacitor until an equilibrium voltage is reached. By knowing the current generated to remove from the capacitor the voltage placed thereon by the input current signal, then the total charge applied to the capacitor can be determined. Further digital processing of the input signal value may be done without the use of a complicated digital to analog converter.