Precision gyroscope mode-matching insensitive to rate input
AssigneeThe Regents of the University of California
InventorsBernhard E. Boser, Burak Eminoglu
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Abstract
A precision gyroscope which provides mode matching which is insensitive to rate input in response to continuously monitoring the split between the resonances of the drive and sense modes. A calibration signal, having at least one modulated term whose carrier is synchronous with the excitation in the drive resonator is utilized to modify the feedback signal in the sense resonator. The gyroscope thus does not suffer from corruption of, or from, the rate measurement; whereas the frequency of the calibration signal can be chosen independently of the bandwidth of the rate input.
Claims18
A force-feedback gyroscope apparatus, comprising:
- a first resonator as a drive resonator having an x-mode excited at its resonant frequency;
- a second resonator as a sense resonator having a y-mode which is driven by receiving a Coriolis force signal from the output of said first resonator;
- wherein said second resonator has a feedback signal which combines the y-mode output signal with a calibration signal that is synchronous with the excitation in the x-mode, and modulated at one or more calibration frequencies within the bandwidth of the angular rate input;
- wherein the calibration signal, Ycal(t), is the sum of two periodic signals with calibration frequencies ωcal1 and ωcal2 and carriers which are modulated in-phase and quadrature with the x-mode displacement;
- wherein said calibration signal Ycal(t) is generated in response to the relation:
- Ŷcal1·cos (ωxt+Θerr) sin (ωcal1t)+Ŷcal2·sin (ωxt+Θerr) sin (ωcal2t);
- and
- wherein Ŷcal1 is a first calibration input, ωx is the tone frequency of the x-mode of said first resonator, t is time, ωcal1 is a first calibration tone frequency and ωcal2 is the second calibration tone, and Θerr represents an arbitrary but constant phase shift and accounts for processing delay.
Dependencies are inferred from the claim text.