Abstract: A disk drive is disclosed comprising a disk, a head, and control circuitry comprising a servo control system operable to actuate the head over the disk. A vibration signal VS(k) is measured representing a disturbance in the servo control system. A first future value of the vibration signal VS(k) is predicted based on: VS1(k+1)=?1[VS(k)?VS(k?1)]+VS(k) where ?1 is a first scalar corresponding to a first frequency range. A second future value of the vibration signal VS(k) is predicted based on: VS2(k+1)=?2[VS(k)?VS(k?1)]+VS(k) where ?2 is a second scalar corresponding to a second frequency range different from the first frequency range.

Abstract: A disk drive is disclosed comprising a disk, a head, and control circuitry comprising a servo control system operable to actuate the head over the disk. A plurality of disturbance signals is generated in response to a vibration. A plurality of correlations is generated in response to each disturbance signal and an error signal of the servo control system. At least one of the disturbance signals is selected in response to the correlations. A feed-forward compensation value is generated in response to the selected disturbance signal, and the feed-forward compensation value is applied to the servo control system to compensate for the vibration.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, and control circuitry including a shock detector. A shock threshold of the shock detector is initialized, and a first number of shock events is detected in response to the shock detector operating at the initial shock threshold. When the first number of shock events exceeds an upper event threshold, a control signal is adjusted in order to adjust a frequency spectrum of noise affecting the shock detector. After adjusting the control signal, a second number of shock events is detected in response to the shock detector operating at the initial shock threshold. When the second number of shock events exceeds the upper event threshold, the shock threshold is increased.

Abstract: A disk drive is disclosed comprising a disk, a head, an actuator for actuating the head over the disk, and control circuitry comprising a servo control system for controlling the actuator. A compensation value is generated based on a speaker driver signal, and the actuator is controlled using the compensation value.

Abstract: A disk drive is disclosed comprising a disk, a head, and control circuitry comprising a servo control system operable to actuate the head over the disk. A plurality of disturbance signals is generated in response to a vibration. A plurality of correlations is generated in response to each disturbance signal and an error signal of the servo control system. At least one of the disturbance signals is selected in response to the correlations. A feed-forward compensation value is generated in response to the selected disturbance signal, and the feed-forward compensation value is applied to the servo control system to compensate for the vibration.

Abstract: Systems and methods for writing data to a disk under write disturbance conditions are provided. In one embodiment, a disk drive comprises a disk and a detection system configured to detect a write disturbance condition. The disk drive further comprises a controller configured to alternately operate in a normal mode and a write disturbance mode, wherein, the controller is configured to write data to data tracks on the disk in the normal mode and to write data to data tracks on the disk that are spaced farther apart in the write disturbance mode, and the controller is configured to switch from the normal mode to the write disturbance mode when the detection system detects the write disturbance condition.

Abstract: A computer system is disclosed comprising a disk drive comprising a head stack assembly (HSA), the HSA comprising a spindle motor for rotating at least one disk, and at least one head actuated over the disk. The computer system further comprises a host coupled to the disk drive, wherein the host comprises a microprocessor operable to first boot the host by reading boot data from a secondary storage device. After first booting the host, the microprocessor commands the disk drive to accumulate performance data for the HSA, and after accumulating the performance data, the microprocessor second boots the host by reading boot data from the HSA.

Abstract: Adaptive shock detection systems are provided according to various embodiments of the present invention. In one embodiment, an adaptive shock detection system comprises a shock sensing circuit, and a controller configured to receive shock detection signals from the shock sensing circuit and to dynamically adjust a sensitivity of the shock sensing circuit based the received shock detection signals.

Abstract: A disk drive is disclosed comprising a disk, and a head actuated radially over the disk. A first linear acceleration signal is generated representing a first acceleration disturbance, a second linear acceleration signal is generated representing a second acceleration disturbance, and a third linear acceleration signal is generated representing a thermal popping disturbance. The first linear acceleration signal is combined with the third linear acceleration signal to generate a fourth linear acceleration signal representing a combined physical shock disturbance and thermal popping disturbance.