Self-writing of servo patterns
View Patent ↗Various embodiments of the present invention allow for the generation of at least one estimated value of a first parameter that is derived from a regularly measured value of a second parameter. In addition, a single control feedback signal can be adjusted via updating of the estimated and regularly measured values in a control feedback loop. At least one spiral track can be written to storage media based on the single control feedback signal, where the single control feedback signal can be received from an compensating circuit that receives the at least one estimated value of the first parameter, which can refer to position, and the at least one regularly measured value, which can refer to velocity.
1. A method, comprising:
generating at least one estimated value of a first parameter from at least one regularly measured value of a second parameter;
updating the at least one estimated value of the first parameter with at least one of an irregularly measured value of the first parameter;
and adjusting an output of a control feedback loop utilizing the at least one updated, estimated value of the first parameter and the at least one regularly measured value of the second parameter,
wherein the updating of the at least one estimated value of the first parameter comprises resetting the at least one estimated value of the first parameter to the at least one irregularly measured value of the first parameter.
2. The method of claim 1 , wherein the first parameter is a position measurement of a transducer head controlled by a voice coil motor relative to at least one reference track.
3. The method of claim 2 , wherein the at least one reference track is written at a predetermined radius of a disk media at one of a constant and non-constant interval.
4. The method of claim 1 , wherein the second parameter is an actual velocity measurement associated with a back electromotive force of the voice coil motor.
5. The method of claim 1 , wherein the at least one irregularly measured value of the first parameter is determined at a first sampling rate, wherein the first sampling rate is substantially lower than a second sampling rate with which the at least one regularly measured value of the second parameter is determined.
6. The method of claim 1 , wherein the updating of the at least one estimated value of the first parameter further comprises integrating the at least one regularly measured value of the second parameter as a function of time, wherein the time is indicative of at least one sample instance at which the at least one irregularly measured value of the first parameter is measured.
7. The method of claim 1 , wherein the output of the control feedback loop controls movement of a voice coil motor.
8. The method of claim 7 , wherein the adjusting of the output of the control feedback loop occurs concurrently with writing a reference pattern for subsequent writing of servo data executed by a read and write head operatively connected to the voice coil motor.
9. A method, comprising:
receiving a single control signal, wherein the single control signal is a function of a plurality of velocity data and a plurality of estimated position data; and
writing at least one spiral track to a media in accordance with the single control signal.
10. The method of claim 9 , wherein the plurality of velocity data is determined by measuring at a first sampling rate, a back electromotive force associated with a voice coil motor configured to perform the writing of the at least one spiral track.
11. The method of claim 9 , wherein the plurality of estimated position data is determined by applying an integration function to the plurality of velocity data, the plurality of velocity data being in one of a filtered and a non-filtered format.
12. The method of claim 11 , wherein the integration function is further applied with regard to irregular sample instances at which at least a first value representative of the at least one spiral track coincides with at least a second value representative of at least one reference track already written on the media.
13. The method of claim 9 , wherein the plurality of estimated position data is updated with a plurality of actual position data measured at irregular sample instances.
14. The method of claim 9 , wherein the plurality of velocity data is constructed from the plurality of actual position data, the plurality of actual position data being measured relative to an inner diameter and outer diameter of the media.
15. A system, comprising:
an estimating circuit configured to generate estimated position measurements derived as a function of velocity measurements;
a compensating circuit configured to receive the estimated position measurements and the velocity measurements from the estimating circuit, and to generate a single control feedback loop output; and
writing circuitry configured to self-write at least one spiral track onto a disk media based upon the single control feedback loop output received from the compensating circuit.
16. The system of claim 15 , wherein a first set of the estimated position measurements are updated when at least one portion of the at least one spiral track crosses at least one portion of at least one reference track.
17. The system of claim 16 , wherein the first set of the estimated position measurements are indicative of a first set of instances when the at least one portion of the at least one spiral track crosses the at least one portion of the at least one reference track occur at irregular intervals of time.
18. The system of claim 17 , wherein a second set of the estimated position measurements are derived from the velocity measurements.
19. The method of claim 18 , wherein the second set of the estimated position measurements are derived from the velocity measurements using an integration function, the velocity measurements being determined at regular intervals of time indicative of a second set of instances, wherein the second set of instances substantially outnumber the first set of instances.