US 12,456,486 B1 · Digital-filter engine with pre-compute of output

Abstract

A digital filter completes a portion of digital filter operations performed on a control signal before the control signal has been determined. Calculation delay associated with performing digital filter operations on the control signal can be reduced and stability of the servo control system improved. For a particular servo wedge of a storage disk, an estimated control signal is used to determine a pre-computed first output of a digital filter before an actual control signal for that particular servo wedge has been determined. Then, once the actual control signal for the servo wedge has been determined, an implemented second output of the digital filter is determined based on the pre-computed first output and a difference between the estimated control signal and the actual control signal. The implemented second output of the digital filter is used to control magnetic head position in response to crossing the servo wedge.

Claims20

Dependent claims

A method of controlling an actuator for a magnetic head of a disk drive via a digital filter, the method comprising:

determining a first output of the digital filter for a first servo wedge, based on a set of state variable values associated with the digital filter and an estimated control input to the digital filter;
after determining the first output, receiving an actual control input for the digital filter that is based on position information associated with the magnetic head crossing the first servo wedge;
determining a second output of the digital filter for the first servo wedge based on the first output, the estimated control input, and the actual control input;
and
applying the second output of the digital filter to the actuator.

2 more elements

Dependencies are inferred from the claim text.

Digital-filter engine with pre-compute of output

Life of this patent

Digital-filter engine with pre-compute of output

Life of this patent

Abstract

Claims20