Synchronized mass gyroscope

• US 10,415,968 B2
• Filed: 12/19/2016
• Issued: 09/17/2019
• Est. Priority Date: 12/19/2016
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Prikhodko, Igor P., Geen, John A., Gregory, Jeffrey A.
• Primary Examiner(s): Woodward, Nathaniel T
• Application Number:
  US15/383,318
• Publication Number:
  US 20180172447A1
• Time in Patent Office: 1,002 Days
• Field of Search: 7350412
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01P 15/14 by making use of gyroscopes gyroscopes per se G01C19/00

Abstract

Micromachined inertial devices are presented having multiple linearly-moving masses coupled together by couplers that move in a linear fashion when the coupled masses exhibit anti-phase motion. The couplers move in opposite directions of each other, such that one coupler on one side of the movable masses moves in a first linear direction and another coupler on the opposite side of the movable masses moves in a second linear direction opposite the first linear direction. The couplers ensure proper anti-phase motion of the masses.

Claims

1. A synchronized mass microelectromechanical systems (MEMS) device, comprising:

a substrate;

a first proof mass coupled to the substrate by a first tether and configured to move linearly parallel to each of first and second transverse axes;

a second proof mass coupled to the substrate by a second tether and configured to move linearly parallel to each of the first and second transverse axes;

a third proof mass coupled to the substrate by a third tether and configured to move linearly parallel to each of the first and second transverse axes;

a fourth proof mass coupled to the substrate by a fourth tether and configured to move linearly parallel to each of the first and second transverse axes; and

a first coupler coupling the first and second proof masses together and configured to move linearly parallel to the first axis when the first proof mass moves in a first direction parallel to the second axis and the second proof mass moves in a second direction opposite the first direction parallel to the second axis.

2. The MEMS device of claim 1, further comprising a second coupler coupling the third and fourth proof masses together and configured to move linearly parallel to the first axis when the third proof mass moves in the second direction parallel to the second axis and the fourth proof mass moves in the first direction parallel to the second axis.

3. The MEMS device of claim 2, wherein the first coupler and second coupler are configured to move linearly in opposite directions as each other.

4. The MEMS device of claim 2, wherein the first and second couplers are configured to move linearly in a same direction as each other.

5. The MEMS device of claim 2, further comprising a third coupler coupling the first and third proof masses together and a fourth coupler coupling the second and fourth proof masses together, wherein the third and fourth couplers are configured to move linearly parallel to the second axis when the first and third proof masses move linearly in anti-phase motion parallel to the first axis and the second and fourth proof masses move linearly in anti-phase motion parallel to the first axis.

6. The MEMS device of claim 2, further comprising a third coupler coupling the first and second proof masses, wherein the first and third couplers are linearly arranged with respect to each other.

7. The MEMS device of claim 1, wherein the MEMS device comprises a plurality of couplers including the first coupler, and wherein the plurality of couplers are configured in combination to enforce linear anti-phase motion of the first and third proof masses parallel to the first axis and to enforce linear anti-phase motion of the first and second proof masses parallel to the second axis, and wherein the couplers of the plurality of couplers are configured to move linearly.

8. The MEMS device of claim 7, wherein the couplers of the plurality of couplers have masses selected such that, in combination, they provide substantially zero net momentum when linearly translating.

9. A method of operating a synchronized mass microelectromechanical systems (MEMS) device having four proof masses coupled together, the method comprising:

moving a first proof mass and a second proof mass of the four proof masses in linear anti-phase motion parallel to a first axis;

moving a third proof mass and a fourth proof mass of the four proof masses in linear anti-phase motion parallel to the first axis;

linearly translating a first coupler coupling the first and second proof masses of the four proof masses when the first and second proof masses of the four proof masses move in linear anti-phase motion parallel to the first axis; and

linearly translating a second coupler coupling the third and fourth proof masses of the four proof masses when the third and fourth proof masses of the four proof masses move in linear anti-phase motion parallel to the first axis.

10. The method of claim 9, wherein linearly translating the first coupler and linearly translating the second coupler comprises linearly translating the first and second couplers parallel to a second axis transverse to the first axis.

11. The method of claim 9, wherein linearly translating the first coupler and linearly translating the second coupler comprises linearly translating the first and second couplers in opposite directions as each other.

12. The method of claim 9, further comprising moving the first and third proof masses of the four proof masses in linear anti-phase motion parallel to a second axis transverse to the first axis, moving the second and fourth proof masses of the four proof masses in linear anti-phase motion parallel to the second axis, linearly translating a third coupler coupling the third proof mass with the first proof mass when the first and third proof masses of the four proof masses move in linear anti-phase motion parallel to the second axis, and linearly translating a fourth coupler coupling the fourth proof mass with the second proof mass when the second and fourth proof masses of the four proof masses move in linear anti-phase motion parallel to the second axis.

13. The method of claim 9, further comprising linearly translating a plurality of couplers including the first and second couplers in momentum-balanced operation.

14. The method of claim 9, wherein moving the first proof mass and the second proof mass of the four proof masses in linear anti-phase motion parallel to the first axis and moving the third proof mass and the fourth proof mass of the four proof masses in linear anti-phase motion parallel to the first axis comprises driving the four proof masses, wherein the method further comprises sensing rotation of the synchronized mass MEMS device by moving the first and third proof masses of the four proof masses in linear anti-phase motion parallel to a second axis transverse to the first axis and moving the second and fourth proof masses of the four proof masses in linear anti-phase motion parallel to the second axis, and wherein the method further comprises enforcing linear anti-phase motion of the first and second proof masses along the first axis and enforcing linear anti-phase motion of the first and third proof masses along the second axis using a plurality of linearly-translating couplers.

15. The method claim 9, further comprising linearly translating a third coupler coupling the first and second proof masses in a direction opposite to that in which the first coupler is translated.

16. A synchronized mass, balanced microelectromechanical systems (MEMS) gyroscope, comprising:

a substrate;

first, second, third, and fourth proof masses suspended above and coupled to the substrate and each configured to translate linearly parallel to first and second axes; and

means for enforcing linear anti-phase motion of the first and second proof masses parallel to the first axis.

17. The synchronized mass, balanced MEMS gyroscope of claim 16, further comprising means for enforcing linear anti-phase motion of the first and third proof masses parallel to the second axis.

18. The synchronized mass, balanced MEMS gyroscope of claim 17, wherein the means for enforcing linear anti-phase motion of the first and second proof masses parallel to the first axis and the means for enforcing linear anti-phase motion of the first and third proof masses parallel to the second axis includes means for providing momentum balanced operation of the synchronized mass, balanced MEMS gyroscope.

19. The synchronized mass, balanced MEMS gyroscope of claim 18, further comprising means for inhibiting quadrature of the four proof masses.

20. The synchronized mass, balanced MEMS gyroscope of claim 16, further comprising means for inhibiting quadrature of the four proof masses.