US 11,862,196 B1Granted

Split-actuator drive that coordinates fractional-wedge timing of aggressor and victim for effective victim feedforward

AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation

InventorRichard M. Ehrlich

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Abstract

A method reduces the effect of accelerating/decelerating an “aggressor actuator” in a multi-actuator drive on a “victim actuator” in the drive. Measurements of fractional-wedge timing-offsets for an aggressor head are used to adjust the aggressor actuator commands that are inputted to a victim disturbance feedforward signal generator when a timing offset exists between the currently-used aggressor head and the aggressor head that was used to measure transfer functions for determining victim feedforward signals. When such a timing offset is equivalent to a specific fraction of the time period separating servo wedges, values of the aggressor actuator commands that are inputted to the victim disturbance feedforward signal generator may be modified based on the specific fraction. Feedforward signals may be modified when a timing offset exists between and the current timing of the currently-used victim head and an original timing of the currently-used victim head.

Claims20

Dependent claims

A computer-implemented method of controlling magnetic head position in a disk drive that includes a first head for accessing a first recording surface and a second head for accessing a second recording surface, the method comprising:

determining first and second control signals that each cause a first actuator to position the first head relative to the first recording surface, wherein the first control signal is based on a first position signal generated by the first head passing over a first servo wedge disposed on the first recording surface and the second control signal is based on a second position signal generated by the first head passing over a second servo wedge disposed on the first recording surface;
determining a feedforward value that modifies a third control signal that is determined based on a third position signal, wherein the third position signal is generated by the second head passing over a third servo wedge disposed on the second recording surface and the third control signal causes a second actuator that is coupled to the second head to position the second head relative to the second recording surface;
determining that the third position signal is generated by the second head passing over the third servo wedge;
and
modifying the third control signal with the feedforward value in response to the second head passing over the third servo wedge,
wherein the feedforward value is generated based on the first and second control signals.

3 more elements

A disk drive, comprising:

a first head for accessing a first recording surface of the disk drive and a second head for accessing a second recording surface of the disk drive;
and
a controller configured to perform the steps of:
determining first and second control signals that each cause a first actuator to position the first head relative to the first recording surface, wherein the first control signal is based on a first position signal generated by the first head passing over a first servo wedge disposed on the first recording surface and the second control signal is based on a second position signal generated by the first head passing over a second servo wedge disposed on the first recording surface;
determining a feedforward value that modifies a third control signal that is determined based on a third position signal, wherein the third position signal is generated by the second head passing over a third servo wedge disposed on the second recording surface and the third control signal causes a second actuator that is coupled to the second head to position the second head relative to the second recording surface;
determining that the third position signal is generated by the second head passing over the third servo wedge;
and
modifying the third control signal with the feedforward value in response to the second head passing over the third servo wedge,
wherein the feedforward value is generated based on the first and second control signals.

6 more elements

Dependencies are inferred from the claim text.