Micro-gyrometer with frequency detection

• US 20060032306A1
• Filed: 08/12/2005
• Published: 02/16/2006
• Est. Priority Date: 08/13/2004
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Robert, Philippe
• Granted Patent: US 7,389,690 B2
• Time in Patent Office: Days
• US Class Current: 73/504.20
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

This invention suggests a micro-gyrometer, advantageously machined using conventional micro-electronic techniques, based on the detection of Coriolis forces generated by an angular movement Ω perpendicular to the direction of vibration of the masses free to move along the plane of the gyrometer. Coriolis forces are detected through the movement that they apply to the natural mode of a resonator coupled to the moving device.

Claims

1. Gyrometer comprising:

a first excitation resonator, free to move in a plane, comprising two masses connected to each other by connecting means;

excitation means for putting masses into movement in a first direction of the plane;

at least one second detection resonator connected to the first resonator;

means of exciting the second resonator and measuring the frequency of its natural mode.

2. Gyrometer according to claim 1, also comprising a substrate to which each resonator is connected through at least one anchor point.

3. Gyrometer according to claim 2, wherein the substrate is a microtechnological support, the gyrometer being monolithic.

4. Gyrometer according to claim 1, wherein means of putting the masses into movement are fixed capacitive combs.

5. Gyrometer according to claim 1, wherein the connecting means comprise two connecting arms parallel to the first movement direction of the masses, and connected to the masses through bending arms, such that the connecting arms are perpendicular to the Coriolis force generated by the movement of the masses in the first direction and a rotation of the first excitation resonator from an axis perpendicular to the plane.

6. Gyrometer according to claim 5, wherein each connection arm is connected to a torsion axis.

7. Gyrometer according to claim 6, comprising a first second detection resonator connected to a first connecting arm at a first distance from the torsion axis.

8. Gyrometer according to claim 7, also comprising another second detection resonator connected to the second connecting arm at a second distance from the torsion axis.

9. Gyrometer according to claim 8, wherein the first and the second distances are equal, and wherein the detection resonators are connected to the first and second arms between the corresponding torsion axis and the same mass.

10. Gyrometer according to claim 9 wherein the detection resonators are chosen from among the vibrating arms or tuning fork-shaped resonators.

11. Gyrometer according to claim 7, comprising two second detection resonators connected to a first connecting arm symmetrically about the torsion axis.

12. Gyrometer according to claim 11, also comprising two second detection resonators connected to the second connecting arm, symmetric about the torsion axis and at the first distance from the torsion axis.

13. Gyrometer according to claim 12, wherein the second detection resonators are chosen from among the vibrating beams or tuning fork-shaped resonators.

14. Gyrometer according to claim 5, wherein the second detection resonator is connected to a rigid arm hinged about it.

15. Gyrometer according to claim 1, wherein the second detection resonators are connected to means for amplifying the force exerted on them by the first excitation resonator.

16. Gyrometer according to claim 15, wherein the amplification means comprise rigid arms hinged about a resonant element.

17. Gyrometer according to claim 15, wherein the second detection resonators are chosen from among the vibrating beams or tuning fork-shaped resonators.

18. Gyrometer according to claim 1, comprising means for activating each second resonator.

19. Gyrometer according to claim 18, wherein the means for activating the second resonators are capacitive type means.

20. Gyrometer according to claim 19, wherein the gyrometer is monolithic.