PQ enhanced dual stage servo controller
AssigneeSeagate Technology LLC
InventorTravis E. Ell
Life of this patent
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Abstract
A servo controller controls the servo system in a disc drive. A proportional integrator component receives the target track signal indicative of a target track and a measured track signal indicative of actual or measured data head position. During seek mode, the proportional integrator provides an output signal based on the measured track signal and the target track signal. A profile generator component provides a profile signal based on the output signal from the proportional integrator. A coarse actuator is driven based on the profile signal. A filter component is coupled to the profile generator and filters the profile signal to provide a filtered profile signal. The fine actuator is driven based on the filtered profile signal.
Claims20
A servo system controlling positioning of a data head relative to a disc surface on a disc in a disc drive, the servo system comprising:
- a coarse actuator coupled to the data head to move the data head;
- a fine actuator coupled to the data head to move the data head relative to the coarse actuator;
- a control system having a fine actuator control component and a coarse actuator control component wherein the fine and coarse actuator control components are configured such that, at a frequency at which both the fine and coarse actuator control components have approximately equal gains, a phase difference between outputs of the fine and coarse actuator control components is less than approximately 120 degrees, for track seek operations.
A servo system controlling positioning of a data head relative to a disc surface on a disc in a disc drive, the servo system comprising:
- a coarse actuator coupled to the data head to move the data head;
- a fine actuator coupled to the data head to move the data head relative to the coarse actuator;
- and
- a servo controller configured to control actuation of the coarse and fine actuators during track seek operations, the servo controller comprising at least a proportional integrator component.
A servo control system comprising:
- a profile generator component configured to provide a profile signal to drive a coarse actuator based on a received input signal, the input signal based on:
- a measured track signal and a target track signal, during a track seek operation;
- and
- the target track signal, an error signal and a bias signal, during a settle operation;
- and
- a filter component coupled to the profile generator to provide a filtered profile signal to drive at least one fine actuator during the track seek operation, the filtered profile signal having a low corner frequency that is reduced from that in the profile signal.
Dependencies are inferred from the claim text.