Ring Gyroscope Structural Features

Patent metadata

Field	Value
Publication number	US-2016123735-A1
Application number	US-201414532256-A
Country	US
Kind code	A1
Filing date	Nov 4, 2014
Priority date	Nov 4, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

Novel structural features applicable to a variety of inertial sensors. A composite ring composed of concentric subrings is supported by a compliant support structure suspending the composite ring relative to a substrate. The compliant support structure may either be interior or exterior to the composite ring. The compliant support may be composed of multiple substantially concentric rings coupled to neighboring rings by transverse members regularly spaced at intervals that vary with radius relative to a central axis of symmetry. Subrings making up the composite ring may vary in width so as to provide larger displacement amplitudes at intermediate radii, for example. In other embodiments, electrodes are arranged to reduce sensitivity to vibration and temperature, and shock stops are provided to preclude shorting in response to shocks.

First claim

What is claimed is:

1 . A resonator comprising:
a. a plurality of rings forming a composite ring, the plurality of rings disposed concentrically with respect to an axis, each of the plurality of rings characterized by a radius and by an annular width, each of the plurality of rings coupled to a neighboring ring by a plurality of coupling beams, each of the coupling beams oriented substantially radially with respect to the axis; b. a compliant support structure adapted to suspend the plurality of rings relative to a substrate; and c. at least one actuator configured to drive the plurality of rings in a plurality of coupled oscillatory modes.

2 . A resonator according to claim 1 , wherein the annular widths of the plurality of rings varies as a specified function of the radius of the respective ring.

3 . A resonator according to claim 1 , wherein at least one of the plurality of coupling beams is stiff.

4 . A resonator according to claim 1 , wherein all of the plurality of coupling beams are stiff.

5 . A resonator according to claim 1 , wherein the plurality of coupling beams between any one of the plurality of rings and a neighboring ring are spaced at equal spacing angles around the axis of the rings.

6 . A resonator according to claim 5 , wherein the spacing angles are the same between each of the plurality of rings of the composite ring and its neighboring ring.

7 . A resonator according to claim 5 , wherein the spacing angles vary between rings of the plurality of rings as a function of radius of the rings.

8 . A resonator according to claim 1 , wherein the compliant support structure includes a lattice of concentric rings and radial members.

9 . A resonator according to claim 1 , wherein the compliant support structure is coupled to a substrate via an anchor interior to all of the concentric rings.

10 . A resonator according to claim 1 , further comprising at least one sensing electrode for sensing vibration amplitude of one of the plurality of concentric rings.

11 . A resonator according to claim 10 , wherein a first sensing electrode is disposed at an inner edge of the composite ring and a second sensing electrode is disposed at an outer edge of the composite ring.

12 . A resonator according to claim 10 , wherein the at least one sensing electrode is disposed at a locus characterized by a local maximum displacement less than an overall maximum transverse displacement of the composite ring.

13 . A resonator according to claim 1 , wherein the annular width of each of the plurality of rings of the composite ring varies with the radius of the ring according to a specified function.

14 . A resonator according to claim 1 , wherein each of the plurality of rings which together constitute the composite ring is characterized by a substantially identical resonance frequency.

15 . A resonator according to claim 1 , wherein the compliant support structure is adapted to suspend the plurality of rings relative to a substrate at a radius larger than any of the plurality of rings.

16 . A resonator according to claim 15 , wherein the compliant support structure comprises:
a. an inner edge coupled to the composite ring; and b. an outer edge coupled to an outside anchor.

17 . A resonator according to claim 15 , further comprising at least one sensor disposed at a radius from the axis smaller than that of any of the plurality of rings of the composite ring, and at least one sensor disposed at a radius from the axis larger than any radius of any of the plurality of rings of the composite ring.

18 . A ring gyroscope comprising:
a. an annular composite ring proof mass characterized by an inner side and an outer side; b. a compliant support structure for supporting the annular composite ring; c. a plurality of drive electrodes disposed at a first of the inner side and the outer side; and d. a plurality of sense electrodes disposed at a second of the inner side and the outer side, wherein the first and second sides are complementary, wherein each drive electrode is a member of a triplet of drive electrodes, each triplet of electrodes comprising:
(i.) an inner segment for applying to the proof mass a first of an AC forcing signal and a tuning voltage; and
(ii.) two outer segments straddling the inner segment for applying a second of the AC forcing signal and the tuning voltage.

19 . A ring gyroscope comprising:
a. an annular composite ring proof mass characterized by an inner side and an outer side with respect to a central axis; b. a compliant support structure for supporting the proof mass; c. a plurality of electrodes, each of the electrodes serving for at least one of driving, sensing and tuning at least one vibrational mode of the proof mass, each of the plurality of electrodes disposed at one of the inner side and the outer side of the proof mass; and d. a first shock stop disposed between a first pair of the electrodes, the first shock stop extending in a radial direction toward the proof mass, such that displacement of the proof mass in a radial direction results in contact with a shock stop prior to contact with any electrode.

20 . A ring gyroscope according to claim 19 , further comprising a second shock stop disposed between a second pair of the electrodes, wherein at least one electrode of the first pair of electrodes is distinct from one electrode of the second pair of electrodes.

21 . A ring gyroscope according to claim 20 , wherein the first and second shock stops are coupled via a structural member.

Assignees

• Analog Devices Inc

Inventors

• Gregory Jeffrey A
• Prikhodko Igor P

Classifications

• G01C19/5684 Primary

  the devices involving a micromechanical structure · CPC title

• G01C19/567

  using the phase shift of a vibration node or antinode · CPC title

• G01C19/5677 Primary

  of essentially two-dimensional [2D] vibrators, e.g. ring-shaped vibrators · CPC title