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 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 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 data recording disk drive has one or more capacitive sensors for sensing out-of-plane vibration of the disk or disks. The sensors are attached to a support structure that is attached to the disk drive housing. Each sensor is associated with a disk and faces a surface of the disk near the outer perimeter of the disk and close to the recording head. The support structure can be made of a metal or a high-strength plastic and can be a separate structure mounted to the housing, or integrated as part of the single-piece housing casting. If it is metallic, as would be the case if it were integrated with the housing, then layers of insulating material separate the sensors from the support structure. A support structure that serves other functions in the disk drive, such as support for disk damping plates, can also function as the support structure for the capacitive sensors.
摘要:
A data recording disk drive has a plurality of capacitive sensors, each sensor facing a surface of an associated disk, a capacitance sensing circuit for converting the sensed capacitance to a voltage representative of the distance between the sensor and the disk surface, and a feedforward controller that receives the voltage signal. The feedforward controller has a transfer function with gain and phase characteristics designed to match the transfer function from the out-of-plane disk vibration to the position of the read/write head while accounting for the effects of the sensor dynamics and the dynamics of the actuator. The output from the feedforward controller is combined with the output from the disk drive's servo feedback controller so that the effects of disk vibration on track misregistration of the head are removed from the control signal to the actuator.
摘要:
A data recording disk drive has one or more capacitive sensors for sensing out-of-plane vibration of the disk or disks. The sensors are attached to a support structure that is attached to the disk drive housing. Each sensor is associated with a disk and faces a surface of the disk near the outer perimeter of the disk and close to the recording head. The support structure can be made of a metal or a high-strength plastic and can be a separate structure mounted to the housing, or integrated as part of the single-piece housing casting. If it is metallic, as would be the case if it were integrated with the housing, then layers of insulating material separate the sensors from the support structure. A support structure that serves other functions in the disk drive, such as a support for air dams that extend between the disks, can also function as the support structure for the capacitive sensors.
摘要:
A data recording disk drive has one or more capacitive sensors for sensing out-of-plane vibration of the disk or disks. The sensors are attached to a support structure that is attached to the disk drive housing. Each sensor is associated with a disk and faces a surface of the disk near the outer perimeter of the disk and close to the recording head. The support structure can be made of a metal or a high-strength plastic and can be a separate structure mounted to the housing, or integrated as part of the single-piece housing casting. If it is metallic, as would be the case if it were integrated with the housing, then layers of insulating material separate the sensors from the support structure. A support structure that serves other functions in the disk drive can also function as the support structure for the capacitive sensors.
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 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.