Extended position error signal for analog servo disk drive
View Patent ↗A system and method of extending the position error signal for a disk drive storage system using two digital-to-analog converters in a summing junction, including a typical A-B signal and a track error signal scaled to match a gain of the A-B signal. A track error is calculated. The track error is output to a second digital-to-analog converter. The A-B signal is inverted according to the least significant bit of the grey code of a disk track being read. The inverted A-B signal is output to a first digital-to-analog converter. The inverted A-B signal and the track error are combined using a summer to generate a combined signal. The combined signal is used to generate an extended position error signal.
1. A method of extending a position error signal for a disk drive storage system using at least a first and a second digital-to-analog converter in a summing junction, comprising:
calculating a track error;
outputting a track error signal based on the track error calculated to a second digital-to-analog converter;
inverting an A-B signal; and
outputting the A-B signal to a first digital-to-analog converter.
2. The method of claim 1 , wherein the inverting an A-B signal comprises inverting the A-B signal according to the least significant bit of the grey code of a disk track being read.
3. The method of claim 1 , further comprising:
demodulating at least one of the A-B signal and the track error signal.
4. The method of claim 1 , further comprising:
converting at least one of the A-B signal and the track error signal to analog form.
5. The method of claim 1 , further comprising:
scaling a gain of the A-B signal.
6. The method of claim 5 , further comprising:
scaling a gain of the track error signal.
7. The method of claim 6 , further comprising:
combining the A-B signal scaled and the track error signal scaled to generate a combined signal.
8. The method of claim 1 , further comprising:
transmitting the combined signal to a compensator filter.
9. The method of claim 8 , further comprising:
adjusting a gain of an output of the compensator filter.
10. The method of claim 1 , further comprising:
converting at least one of the A-B signal and the track error to analog form.
11. A system of extending a position error signal for a disk drive storage system using at least a first and a second digital-to-analog converter in a summing junction, comprising:
a track error calculator that calculates a track error;
a track error output that outputs a track error signal based on the track error to a second digital-to-analog converter;
an inverter that inverts an A-B signal; and
an A-B signal output that outputs the A-B signal inverted to a first digital-to-analog converter.
12. The system of claim 11 , wherein the inverter inverts the A-B signal according to the least significant bit of the grey code of a disk track being read.
13. The system of claim 11 , further comprising:
at least one demodulator that demodulates at least one of the A-B signal and the track error signal.
14. The system of claim 11 , wherein at least one of the first digital-to-analog converter and the second digital-to-analog converter converts at least one of the A-B signal and the track error signal to analog form.
15. The system of claim 11 , further comprising:
an A-B signal scaler that scales a gain of the A-B signal.
16. The system of claim 15 , further comprising:
a track error scaler that scales a gain of the track error.
17. The system of claim 16 , further comprising:
a combiner that combines the A-B signal scaled and the track error scaled to generate a combined signal.
18. The system of claim 11 , further comprising:
a transmitter that transmits the combined signal to a compensator filter.
19. The system of claim 18 , further comprising:
an adjuster that adjusts a gain of an output of the compensator filter.