Resonating star gyroscope

• US 7,360,423 B2
• Filed: 01/27/2006
• Issued: 04/22/2008
• Est. Priority Date: 01/29/2005
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Sharma, Ajit, Ayazi, Farrokh, Amini, Babak Vakili, Zaman, Mohammad Faisal
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US11/341,721
• Publication Number:
  US 20060225504A1
• Time in Patent Office: 816 Days
• Field of Search: 735/041.2, 735/041.3
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5677 of essentially two-dimensional vibrators, e.g. ring-shaped vibrators

Abstract

Disclosed are resonant vibratory gyroscopes and fabrication methods relating thereto. The angular motion sensor comprises a resonating star gyroscope which comprises a vibratory solid or shell-type structure for rate sensing or measuring angle of rotation. The structure formed as a merged superposition of two square entities, yields in-plane degenerate flexural modes that are used to sense rotation around the axis perpendicular to the substrate. The resonating star gyroscope may be implemented using the primary flexural degenerate modes. Such an implementation has been successfully demonstrated by the authors using trench-refilled polysilicon and epitaxial polysilicon as the structural material. It is also possible to use a solid star-shaped resonator (with or without perforations) for the gyroscope. The authors also suggest the operation of the resonating star gyroscope employing the higher-order flexural modes. In this particular implementation the authors utilized a (100) single crystalline structural material.

Claims

1. Apparatus, comprising:

a substrate; and

resonator apparatus comprising;

a support member connected to the substrate;

multiple flexural springs coupled to the support member and separated from the substrate that extend outwardly from the support member;

a star-shaped resonator coupled to ends of the flexural springs distal from the support member and separated from the substrate; and

drive and sense electrodes surrounding the star-shaped resonator.

2. The apparatus recited in claim 1 wherein the star-shaped resonator comprises LPCVD or epitaxial polycrystalline silicon.

3. The apparatus recited in claim 1 wherein the star-shaped resonator comprises single crystal silicon having (100) or (111) orientations.

4. The apparatus recited in claim 1 wherein the star-shaped resonator is selected from a group consisting of silicon carbide, quartz, and diamond.

5. The apparatus recited in claim 1 further comprising one or more tuning electrodes surrounding the star-shaped resonator.

6. The apparatus recited in claim 1 wherein the drive and sense electrodes are separated from the star-shaped resonator by gaps.

7. The apparatus recited in claim 5 wherein the one or more tuning electrodes are separated from the star-shaped resonator by gaps.

8. The apparatus recited in claim 1 wherein selected electrodes contact the star-shaped resonator.

9. The apparatus recited in claim 1 wherein the support member and multiple flexural springs are disposed interior to the star-shaped resonator.

10. The apparatus recited in claim 1 wherein the support member and multiple flexural springs are disposed exterior to the star-shaped resonator.

11. The apparatus recited in claim 1 wherein selected electrodes are disposed interior to the star-shaped resonator.

12. The apparatus recited in claim 1 wherein selected electrodes are disposed exterior to the star-shaped resonator.

13. The apparatus recited in claim 1 wherein the star-shaped resonator is comprised of multiple star-shaped shells that are interconnected.

14. he apparatus recited in claim 1 wherein the star-shaped resonator comprises an eight or twelve-faceted star.

15. Apparatus, comprising:

a substrate; and

resonator apparatus comprising;

a support member connected to the substrate;

a multi-faceted star-shaped resonator coupled to the support member and separated from the substrate; and

drive and sense electrodes surrounding the star-shaped resonator.

16. The apparatus recited in claim 15 wherein the star-shaped resonator comprises single crystal silicon having (100) or (111) orientations.

17. The apparatus recited in claim 15 wherein the star-shaped resonator comprises LPCVD or epitaxial polycrystalline silicon.

18. The apparatus recited in claim 15 wherein the star-shaped resonator has perforations in its structure.

19. The apparatus recited in claim 15 wherein the star-shaped resonator is connected to the support member at its center of mass.

20. The apparatus recited in claim 15 wherein the star-shaped resonator is connected to the support member at one or more locations around an inner surface of a periphery of the star-shaped resonator.

21. The apparatus recited in claim 15 wherein the star-shaped resonator comprises an eight or twelve-faceted star.

22. The apparatus recited in claim 15 wherein the star-shaped resonator is perforated or has holes for structural release from the substrate.