Resonant gyroscopes and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-9917571-B2
Application number	US-201514739721-A
Country	US
Kind code	B2
Filing date	Jun 15, 2015
Priority date	Jun 13, 2014
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Certain implementations of the disclosed technology may include systems and methods for high-frequency resonant gyroscopes. In an example implementation, a resonator gyroscope assembly is provided. The resonator gyroscope assembly can include a square resonator body suspended adjacent to a substrate, a ground electrode attached to a side of the resonator body, a piezoelectric layer attached to a side of the ground electrode, a drive electrode in electrical communication with the piezoelectric layer, and configured to stimulate one or more vibration modes of the square resonator body; and a sense electrode in electrical communication with the piezoelectric layer, and configured to receive an output from the square or disk resonator responsive to stimulation of the one or more vibration modes.

First claim

The invention claimed is:

1. A resonator gyroscope assembly comprising:
a square resonator body suspended adjacent to a substrate;
a ground electrode attached to a side of the resonator body;
a piezoelectric layer attached to a side of the ground electrode;
a drive electrode in electrical communication with the piezoelectric layer, and configured to stimulate a first vibration mode of the square resonator body; and
a sense electrode in electrical communication with the piezoelectric layer, and configured to receive an output from the square resonator body responsive to stimulation of a second vibration mode of the square resonator body.

2. The resonator gyroscope assembly of claim 1 , wherein the piezoelectric layer is composed of a material selected from the group consisting of: AlN, ZnO, PZT, GaN, LiNb03, and mixtures thereof.

3. The resonator gyroscope assembly of claim 1 , further comprising a tuning electrode in electrical communication with the piezoelectric layer, and configured to match a resonant frequency of the first vibration mode of the resonator body and a resonant frequency of the second vibration mode of the resonator body.

4. The resonator gyroscope assembly of claim 1 , further comprising a tuning electrode in electrical communication with the piezoelectric layer, and configured minimize a zerorotation rate output voltage.

5. The resonator gyroscope assembly of claim 1 , wherein the first vibration mode and second vibration mode are mutually orthogonal.

6. The resonator gyroscope assembly of claim 1 , wherein the first vibration mode and second vibration mode are degenerate vibration modes.

7. The resonator gyroscope assembly of claim 1 , wherein the first vibration mode and second vibration mode are flexural vibration modes.

8. The resonator gyroscope assembly of claim 1 , wherein the square resonator body is suspended adjacent to the substrate by a suspension support in communication with the substrate.

9. The resonator gyroscope assembly of claim 7 , wherein the suspension supports support a portion of the drive electrode and the sense electrode.

10. A resonator gyroscope assembly comprising:
a resonator body suspended adjacent to a substrate;
a ground electrode attached to a side of the resonator body;
a piezoelectric layer attached to a side of the ground electrode;
a drive electrode in electrical communication with the piezoelectric layer, and configured to detect a first vibration mode of the resonator body;
a sense electrode in electrical communication with the piezoelectric layer, and configured to receive an output from the resonator body responsive to stimulation of a second vibration mode of the resonator body; and
a drive-tuning electrode in electrical communication with the piezoelectric layer, and configured to match a resonant frequency of the first vibration mode of the resonator body and a resonant frequency of the second vibration mode of the resonator body.

11. The resonator gyroscope assembly of claim 10 , wherein the piezoelectric material is composed of a material selected from the group comprising: AlN, ZnO, PZT, GaN, LiNb03, and mixtures thereof.

12. The resonator gyroscope assembly of claim 10 , wherein the resonator body comprises a disk resonator body.

13. The resonator gyroscope assembly of claim 10 , wherein an alternating current signal is applied to the tuning electrode.

14. The resonator gyroscope assembly of claim 10 , wherein the first vibration mode and second vibration mode are mutually orthogonal.

15. The resonator gyroscope assembly of claim 10 , wherein the first vibration mode and second vibration mode are degenerate vibration modes.

16. The resonator gyroscope assembly of claim 10 , wherein the first vibration mode and second vibration mode are flexural vibration modes.

17. The resonator gyroscope assembly of claim 10 , wherein the resonator body is suspended adjacent to the substrate by a suspension support in communication with the substrate.

18. The resonator gyroscope assembly of claim 10 , wherein the resonator body and suspension supports are fabricated from the substrate.

19. The resonator gyroscope assembly of claim 10 , further comprising a linear tuning circuit configured to:
receive a drive input signal corresponding to the displacement of a drive electrode,
produce an output signal corresponding to an integration of the drive input signal multiplied by a scale factor, and
apply the output signal to the drive-tuning electrode.

20. The resonator gyroscope assembly of claim 10 , further comprising a lock-in amplifier, having a sense channel, and a drive channel,
wherein the sense channel is configured to receive a sense input signal from the sense electrode corresponding to the displacement of the sense electrode, and is configured to output a signal proportional to the rate of rotation of the gyroscope, and
wherein the drive channel is configured to receive the drive input signal, and is configured to produce a drive output a signal corresponding to a resonant frequency of the resonator body, and is configured to apply the drive output signal to adrive-stimulating electrode.

21. Method for making a gyroscope resonator comprising:
patterning a drive electrode and a sense electrode on a first side of the substrate,
wherein the substrate comprises a first conductive layer and second conductive layer separated by piezoelectric layer attached to a first semiconductor layer and a second semiconductor layer separated by an insulator layer, and
wherein the patterning removes a portion of the first conductive layer,
patterning a resonator body by removing a portion of the first conductive layer, piezoelectric layer, second conductive layer, and substrate to define a shape of a resonator; and
releasing the resonator body by removing a portion of the second conductor layer and the insulator layer of the substrate disposed approximately adjacent to the resonator body,
wherein the resonator body is composed of a material selected from a group comprising: fused quartz, polysilicon, silicon oxide, monocrystalline silicon, metallic materials, GaAs, silicon carbide, diamond, and mixtures thereof.

22. The method of claim 21 , wherein the piezoelectric layer comprises one or more of AlN, ZnO, PZT, GaN, and LiNb03.

23. The method of claim 21 , wherein the resonator body is a square resonator body.

24. The method of claim 21 , further comprising the step of patterning a drive-tuning electrode onto the first side of the substrate, wherein the patterning removes a portion of the first conductive layer.

25. The method of claim 21 , wherein patterning the resonator body further comprises removing a portion of the first conductive layer and the substrate defining a shape of a suspension support in communication with the substrate and the resonator body.

26. The method of claim 21 , wherein a portion of an electrode is supported by the suspension supports.

27. A method of operating a piezoelectric gyroscope, comprising:
receiving a drive input signal corresponding to a displacement of a drive electrode;
generating an output signal corresponding to an integration of the drive input signal multiplied by a scale factor; and
applying the output signal to a drive-tuning electrode.

28. The method of claim 27 , further comprising:
receiving a sense input signal corresponding to a displaceme

Assignees

• Georgia Tech Res Inst

Inventors

• Ayazi Farrokh
• Tabrizian Roozbeh
• Hodjat-Shamami Mojtaba
• Norouzpour-Shirazi Arashk

Classifications

• H03J1/06 Primary

  Driving or adjusting arrangements; combined with other driving or adjusting arrangements, e.g. of gain control · CPC title

• G01C19/5684

  the devices involving a micromechanical structure · CPC title

• H03J2200/19

  Resonator in MEMS technology · CPC title