Digital servo control system for use in disk drives using driver saturation model
AssigneeRodime PLC
InventorRonald James Kadlec
Life of this patent
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Abstract
A servo control system provides adaptive compensation for a variety of tracking and seek problems found in disk drives. The servo control system is ideally implemented in digital form for accuracy, speed and compactness. A first embodiment includes two modes, a tracking (or position) mode and a seek (or velocity) mode, each mode employing a variety of compensation functions. A second embodiment includes a single comprehensive control system which functions during both tracking and seek operations.
Claims12
A controller for controlling the relative position of a reading device with respect to a recording medium, the relative position being changed during a seek operation through a driver having a saturation characteristic, the controller comprising:
- a) a state space observer including:
- 1) a first state variable estimating the relative position of the reading device and the recording medium;
- 2) a second state variable estimating the velocity of the reading device relative to the recording medium;
- 3) saturation characteristic model means for providing a saturation-period effort signal which models the driver's saturation characteristic selectively alter the first state variable;
- and
- 4) means for governing when the saturation-period effort signal alters the first state variable;
- and
- means for providing an interim effort signal to the state space observer's governing means, so as to selectively prevent the saturation-period effort signal from altering the first state variable.
Dependencies are inferred from the claim text.