Micromechanical coriolis rate of rotation sensor

• US 10,024,663 B2
• Filed: 02/19/2016
• Issued: 07/17/2018
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: Hanking Electronics Hongkong Company Limited
• Original Assignee: Hanking Electronics, Ltd.
• Inventors: Rocchi, Alessandro, Marchetti, Eleonora, Bertini, Lorenzo
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US15/048,020
• Publication Number:
  US 20160169676A1
• Time in Patent Office: 879 Days
• CPC Class Codes: G01C 19/04 Details
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: Y10T 74/1293 Flexure hinges for gyros

Abstract

A micromechanical sensor that can detect shock effects in order to prevent false measurements. The sensor includes a substrate having a measurement axis and a detection axis that are disposed orthogonally to each other, and first and second driving masses disposed in a plane containing the measurement and detection axes. Each of the driving masses is rotatably coupled to the substrate via a central suspension disposed on the detection axis. The sensor includes drive electrodes that generate rotary motions in each of the driving masses about a drive axis thereof. At least one elastic connecting element allows the driving masses to deflect in opposite directions in response to a rate of rotation about the measurement axis but deflect in the same direction in response to a shock condition.

Claims

1. A micromechanical sensor comprising:

a substrate having a measurement axis and a detection axis that are disposed orthogonally to each other;

a first driving mass and a second driving mass disposed in a plane containing the measurement and detection axes, each of the first and second driving masses being rotatably coupled to the substrate via a central suspension that is disposed on the detection axis;

drive electrodes that generate rotary motions in each of the first and second driving masses about a drive axis thereof, the drive axis of each of the first and second driving masses being disposed orthogonally to the measurement and detection axes, the rotary motions causing the first and second driving masses to deflect in opposite directions in response to a rate of rotation about the measurement axis; and

at least one elastic connecting element having a primary axis that extends in a direction parallel to the detection axis, the at least one elastic connecting element being coupled to each of the first and second driving masses such as to synchronize the rotary motions thereof by allowing the first and second driving masses to deflect in opposite directions in response to a rate of rotation about the measurement axis but deflect in a same direction in response to a shock condition.

2. The micromechanical sensor according to claim 1, wherein the at least one elastic connecting element is attached at the outermost end of each of the first and second driving masses in the direction of the measurement axis.

3. The micromechanical sensor according to claim 1, wherein the at least one elastic connecting element comprises a cantilever and an elastic connecting spring.

4. The micromechanical sensor according to claim 3, wherein the elastic connecting spring protrudes into an intermediate space between the first and second driving masses.

5. The micromechanical sensor according to claim 1, wherein the at least one elastic connecting element is disposed between the first and second driving masses.

6. The micromechanical sensor according to claim 1, wherein the at least one elastic connecting element is a first mass that is coupled to the first and second driving masses via connecting springs.

7. The micromechanical sensor according to claim 6, wherein the first mass encloses a second mass and is coupled thereto by means of springs.

8. The micromechanical sensor according to claim 7, further comprising detection elements that are disposed between the substrate and at least one of the first driving mass, the second driving mass, the first mass, and the second mass.

9. The micromechanical sensor according to claim 1, wherein the at least one elastic connecting element is rotatably coupled about the measurement axis to the substrate via an anchor.

10. The micromechanical sensor according to claim 1, further comprising drive elements disposed on the first and second driving masses.

11. The micromechanical sensor according to claim 10, further comprising feedback elements that detect the rotary motions and output control signals to a drive controller.

12. The micromechanical sensor according to claim 1, wherein the first and second driving masses are disposed on the central suspension via a plurality of anchor springs.

13. The micromechanical sensor according to claim 7, further comprising stoppers that limit the displaceability of the first and second driving masses, the first mass and the second mass being disposed between the first and second driving masses and the first mass or between the first mass and the second mass.

14. The micromechanical sensor according to claim 1, further comprising stoppers disposed between the central suspension and at least one of the first and second driving masses.

15. The micromechanical sensor according to claim 12, further comprising stoppers disposed between the substrate and the first and second driving masses or between the substrate and the anchoring springs.

16. The micromechanical sensor according to claim 7, wherein the second mass is rotatably coupled about the measurement axis to the substrate via an anchoring.

17. The micromechanical sensor according to claim 12, wherein the anchor springs are rigid about the measurement axis and allow a rotation about the detection axis and the drive axis.

18. A method to determine a rate of rotation, the method comprising:

in a micromechanical sensor having a measurement axis, a detection axis, and a drive axis that are disposed orthogonally to each other, driving a first driving mass and a second driving mass to generate rotary motions in each of the first and second driving masses about a drive axis thereof; and

in response to a rotation about the measurement axis, detecting a motion about the detection axis; and

synchronizing the rotary motions by coupling to each of the first and second driving masses an elastic connecting element that has a primary axis that extends in a direction parallel to the detection axis, the elastic connecting element allowing the first and second driving masses to deflect in opposite directions in response to a rate of rotation about the measurement axis but deflect in a same direction in response to a shock condition.

19. The method according to claim 18, wherein the deflection of the first and second driving masses in the same direction in response to the shock condition reduces sensitivity due to impact.

20. The method according to claim 18, wherein the elastic connecting element comprises springs that are compressed in a manner such that the first and second driving masses oscillate at a same frequency and are deflected at a same amplitude.