摘要:
A disk drive and a method for operating the disk drive compensates for rotational vibration (RV) by adaptively modifying the gains of two separate linear vibration sensors so the sensor gains are optimal under any given condition. The two sensors provide two signals S1, S2, respectively, to the disk drive's servo control processor that generates the control signal to the voice coil motor (VCM) actuator that controls the positioning of the read/write head. The processor uses S1, S2 and the head position error signal (PES) as inputs to run an adaptive RV feedforward (RVFF) algorithm. The adaptive RVFF algorithm takes the PES and sensor outputs S1 and S2 as inputs, mathematically determines the required correction to the sensor gain factors k1 and k2, respectively, and then adjusts the gain factors k1 and k2 accordingly. Each signal S1, S2 is then modified by its adjusted gain factor k1, k2, respectively. The difference in the modified S1, S2 signals is the RVFF signal that is summed with the control signal to generate the RV-compensated control signal to the VCM actuator.
摘要:
A disk drive and a method for operating the disk drive compensates for rotational vibration (RV) by adaptively modifying the gains of two separate linear vibration sensors so the sensor gains are optimal under any given condition. The two sensors provide two signals S1, S2, respectively, to the disk drive's servo control processor that generates the control signal to the voice coil motor (VCM) actuator that controls the positioning of the read/write head. The processor uses S1, S2 and the head position error signal (PES) as inputs to run an adaptive RV feedforward (RVFF) algorithm. The adaptive RVFF algorithm takes the PES and sensor outputs S1 and S2 as inputs, mathematically determines the required correction to the sensor gain factors k1 and k2, respectively, and then adjusts the gain factors k1 and k2 accordingly. Each signal S1, S2 is then modified by its adjusted gain factor k1, k2, respectively. The difference in the modified S1, S2 signals is the RVFF signal that is summed with the control signal to generate the RV-compensated control signal to the VCM actuator.
摘要:
A disk drive, such as a magnetic recording hard disk drive, has a head positioning servo control system that includes an improved repetitive controller included with the conventional feedback controller for suppressing periodic disturbances. The repetitive controller includes a low-pass filter (LPF) and a time-delay memory with a time delay matched to the period of the periodic disturbance. In a digital implementation, where the head position error signal (PES) is sampled, the time delay is the time for N samples. A subsequent PES sample is summed with the time-delay input sample from N samples earlier and this summed value is input to the LPF. The output of the LPF is added to the subsequent PES sample and the added value is input to the feedback controller. The value of N is adjustable, so the repetitive controller is adaptable to changes in frequency of the periodic disturbance.
摘要:
A dual-stage actuator disk drive has both a rotary primary actuator and a rotary secondary actuator. When the primary actuator initiates a seek there are two torque components acting on the center of mass of the secondary actuator's moving portion. The center of rotation of the moving portion is located at an optimal location relative to the center of mass of the moving portion, which results in cancellation of the two torque components and a secondary actuator that has essentially no resonant frequency in response to a seek by the primary actuator. If the optimal location can not be achieved because of assembly tolerances, then the center of rotation is placed at a distance at least as great as the assembly tolerance from the optimal location.
摘要:
A HDD comprising a temperature sensor disposed inside the HDD configured to periodically measure temperature inside of said hard disk drive; a magnetic disk; a read head; a write head; memory for storing RWO data. The RWO data is a function of a distance between the read head and the write head. The HDD also includes a RWO data adjustor configured to adjust the RWO data in response to a change in temperature of the HDD to compensate for a change in the distance between the read head and the write head based on the change in temperature.
摘要:
An active control mechanism and method for stabilizing a servo-controlled actuator system such as an actuator system in a data recording disk drive by compensating the vibrational modes of the actuator's arm assembly. The control mechanism has a sensing arrangement which can include one or more individual sensors attached to the actuator at locations where they generate signals in phase with the vibrational modes, and especially with all the low-frequency major vibrational modes, of the arm assembly. A control mechanism derives from the signals an adjustment signal consisting of three corrective terms—a stiffening correction, an active damping correction, and an inertia correction by a phase correction. Furthermore, high-frequency out-of-phase modes can be stabilized by appropriately shifting the phase of the signals. The adjustment signal is used in the feedback control loop to stabilize the actuator system.
摘要:
A HDD comprising a temperature sensor disposed inside the HDD configured to periodically measure temperature inside of said hard disk drive; a magnetic disk; a read head; a write head; memory for storing RWO data. The RWO data is a function of a distance between the read head and the write head. The HDD also includes a RWO data adjustor configured to adjust the RWO data in response to a change in temperature of the HDD to compensate for a change in the distance between the read head and the write head based on the change in temperature.
摘要:
A dual-stage actuator disk drive has both a rotary primary actuator and a rotary secondary actuator. When the primary actuator initiates a seek there are two torque components acting on the center of mass of the secondary actuator's moving portion. The center of rotation of the moving portion is located at an optimal location relative to the center of mass of the moving portion, which results in cancellation of the two torque components and a secondary actuator that has essentially no resonant frequency in response to a seek by the primary actuator. If the optimal location can not be achieved because of assembly tolerances, then the center of rotation is placed at a distance at least as great as the assembly tolerance from the optimal location.
摘要:
A magnetic recording disk drive has three vibration sensors mounted to the disk drive base to provide feedforward vibration compensation signals. First and second spaced-apart sensors are aligned generally parallel to a radius from the disk rotational axis to a head position on the disk between the inside diameter position (hID) and outside diameter position (hOD) for detecting rotational vibration about the disk rotational axis and linear vibration in the cross-track direction. A third vibration sensor is aligned generally orthogonal to the primary axes of the first and second vibration sensors for detecting primarily linear vibrations in the along-the-track or track circumferential direction. The disk drive servo control processor calculates, from the signals from the three sensors, a rotational vibration feedforward signal, a radial linear vibration feedforward signal, and a circumferential linear vibration feedforward signal which are summed with the actuator control signal to compensate for the vibrations.
摘要:
A disk drive. The disk drive includes an acceleration sensor, a servo controller, a detection determiner, and a handling processor. The acceleration sensor has an associated resonant frequency. The servo controller is configured to perform servo control for head positioning using frequency components that are obtained by cutting off frequency components including the resonant frequency from output of the acceleration sensor. The detection determiner is configured to detect a frequency band including the resonant frequency from the output of the acceleration sensor to determine whether a magnitude of a voltage amplitude of the frequency band is outside of a specified range. The handling processor is configured to execute a corresponding handling operation if the detection determiner determines that the magnitude of the voltage amplitude of the frequency band is outside of the specified range.