Micromachined gyroscope including a guided mass system

• US 9,170,107 B2
• Filed: 09/30/2013
• Issued: 10/27/2015
• Est. Priority Date: 09/16/2011
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Anac, Ozan, Seeger, Joseph
• Primary Examiner(s): Martin, Laura
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US14/041,810
• Publication Number:
  US 20140026662A1
• Time in Patent Office: 757 Days
• Field of Search: 735/040.2, 735/040.4, 735/041.2, 735/041.4, 735/10, 735/11
• US Class Current: 1/1
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

A gyroscope comprises a substrate and a guided mass system. The guided mass system comprises proof masses and guiding arms disposed in a plane parallel to the substrate. The proof masses are coupled to the guiding arm by springs. The guiding arm is coupled to the substrate by springs. At least one of the proof-masses is directly coupled to the substrate by at least one anchor via a spring system. The gyroscope also comprises an actuator for vibrating one of the proof-masses in the first direction, which causes another proof mass to rotate in the plane. Finally, the gyroscope also includes transducers for sensing motion of the guided mass system in response to angular velocities about a single axis or multiple input axes.

Claims

1. A gyroscope comprising;

a substrate;

a guided mass system, the guided mass system comprising at least one first proof-mass, at least one second proof-mass, and at least one guiding arm;

wherein the at least one first proof-mass, the at least one second proof-mass and the at least one guiding arm are disposed in a plane parallel to the substrate;

wherein the at least one first proof mass is coupled to the at least one guiding arm through at least one first spring;

wherein the at least one second proof-mass is coupled to the at least one first proof-mass through at least one second spring;

wherein the at least one guiding arm is coupled to the substrate through at least one third spring;

wherein the at least one second proof-mass is coupled to the substrate through at least one fourth spring;

an actuator that causes the at least one first proof-mass to vibrate in a first direction and causes the at least one second proof-mass and the at least one guiding arm to rotate in the plane; and

at least one transducer for sensing motion of a portion of the guided mass system out of the plane in response to angular velocity about a first input axis that is in the plane.

2. The gyroscope of claim 1, wherein the at least one guiding arm and the at least one second proof-mass are coupled to the substrate by an anchor.

3. The gyroscope of claim 1, wherein the at least one second proof mass and the at least one guiding arm rotate in a same direction.

4. The gyroscope of claim 1, where in the at least one second proof-mass and the at least one guiding arm rotate in opposite directions.

5. The gyroscope of claim 1, wherein the at least one transducer senses motion of the at least one second proof-mass out of the plane in response to angular velocity about an input axis that is parallel to the first direction.

6. The gyroscope of claim 1, wherein the at least one guiding arm and the at least one first proof-mass are able to rotate out of the plane about a first sense axis, the first sense axis being in the plane and parallel to the first direction.

7. The gyroscope of claim 1, wherein the at least one transducer senses motion of the at least one first proof mass out of the plane in response to the angular velocity about the first input axis;

the first input axis is in the plane and orthogonal to the first direction.

8. The gyroscope of claim 1, wherein the at least one fourth spring is compliant in the plane allowing rotation in the plane and compliant out of the plane allowing rotation around a second sense axis wherein the second sense axis is in the plane and orthogonal to the first direction.

9. The gyroscope of claim 8, wherein the at least one second proof-mass is connected to at least one fifth spring, wherein the at least one fifth spring is connected to at least one rigid element, wherein the at least one rigid element is connected to the fourth spring;

wherein the at least one fifth spring is compliant about a first sense axis.

10. The gyroscope of claim 8, further comprising a second transducer;

wherein the second transducer senses motion of the at least one second proof-mass out of the plane in response to angular velocity about an input axis that is parallel to the first direction.

11. A gyroscope comprising:

a substrate;

a guided mass system, the guided mass system comprising at least one first proof-mass, at least one second proof-mass, at least one center proof-mass, and at least one guiding arm,

wherein the at least one first proof-mass, the at least one second proof-mass, the at least one center proof-mass, and the at least one guiding arm are disposed in a plane parallel to the substrate,

the at least one first proof-mass is coupled to the at least one guiding arm through at least one first spring and the at least one second proof-mass is coupled to the at least one guiding arm through at least one second spring;

the at least one center proof-mass is coupled to the at least one first proof-mass through at least one third spring and the at least one center proof-mass is coupled to the at least one second proof-mass through at least one fourth spring;

the at least one guiding arm is coupled to the substrate through at least one fifth spring;

the at least one center proof-mass is coupled to the substrate by at least one anchor through at least one sixth spring;

wherein the at least one guiding arm allows anti-phase motion of the at least one first proof-mass and the at least one second proof-mass in a first direction in the plane;

an actuator causes the at least one first proof-mass and the at least one second proof-mass to vibrate anti-phase in the first direction, causes the at least one center proof-mass and at least one guiding arm to rotate in the plane; and

at least one transducer for sensing motion of a portion of the guided mass system out of the plane in response to angular velocity about a first input axis that is in the plane.

12. The gyroscope of claim 11 further comprising:

a stress relief frame,

wherein the at least one guiding arm is coupled to the stress relief frame via the at least one fifth spring,

wherein the stress relief frame is coupled to the substrate through an anchor,

wherein the stress relief frame does not vibrate substantially in response to the actuator.

13. The gyroscope of claim 11, wherein the at least one guiding arm, the at least one first proof-mass, and the at least one second proof-mass are able to rotate out of the plane about the first sense axis.

14. The gyroscope of claim 13, wherein the at least one sixth spring is compliant in the plane allowing rotation in the plane and compliant out of the plane allowing rotation around a second sense axis.

15. The gyroscope of claim 11, wherein the at least one center proof-mass is connected to at least one seventh spring, wherein the at least one seventh spring is connected to at least one rigid element, wherein the at least one rigid element is connected to the sixth spring;

wherein the at least one seventh spring is compliant about a first sense axis.

16. The gyroscope of claim 11, wherein the at least one transducer senses motion of the at least one first proof-mass out of the plane in response to the angular velocity about the first input axis;

the first input axis is in the plane and orthogonal to the first direction.

17. The gyroscope of claim 11, further comprising at least one second transducer wherein the at least one second transducer senses motion of the at least one center proof-mass out of the plane in response to angular velocity about an input axis that is parallel to the first direction.

18. A gyroscope comprising:

a substrate;

first and second guided mass systems;

a connecting spring coupling the first and second guided mass systems,

the first and second guided mass systems each comprise, at least one first proof-mass, at least one second proof-mass, at least one center proof-mass, and at least one guiding arm,

wherein the at least one first proof-mass, the at least one second proof-mass, the at least one center proof-mass, and the at least one guiding arm are disposed parallel to the substrate,

wherein the at least one center proof-mass is coupled to the at least one first proof-mass, and the at least one second proof-mass,

wherein the at least one first proof-mass and the at least one second proof-mass are coupled to the at least one guiding arm,

wherein the at least one center proof-mass is coupled to the substrate and the at least one guiding arm is coupled to the substrate,

wherein the at least one center proof-mass is able to rotate about a sense axis in plane and orthogonal to a first direction,

wherein the at least one guiding arm allows anti-phase motion of the at least one first proof-mass and the at least one second proof-mass in a first direction in the plane;

an actuator for vibrating the first and second guided mass systems, that the at least one first proof-mass and the at least one second proof-mass to move anti-phase along the first direction,

wherein the at least one center proof-mass of the first guided mass system and the at least one center proof-mass of the second guided mass system rotate anti-phase about an axis normal to the plane; and

at least one transducer for sensing motion of a portion of the first and second guided mass systems out of the plane in response to an angular velocity about an input axis that is in the plane.

19. The gyroscope of claim 18, wherein the connecting spring couples the at least one first proof-mass of the first guided mass system and the at least one second proof-mass of the second guided mass system.

20. The gyroscope of claim 18, wherein the at least one first proof-mass of the first guided mass system and the at least one first proof-mass of the second guided mass system have anti-phase motion.

21. The gyroscope of claim 18, wherein the first guided mass system rotates about a first axis, the second guided mass system rotates about a second axis, the first and second guided mass systems rotates anti-phase about the first and second axes, wherein the first and second axes are in the plane and parallel to the first direction.

22. The gyroscope of claim 18, the at least one transducer senses motion of the at least one center proof-mass of the first and second guided mass systems in response to angular velocity about an axis in the plane and parallel to the first direction.

23. The gyroscope of claim 22, further comprising at least one second transducer for sensing motion of the at least one first and second proof-masses of the first and second guided mass systems in response to angular velocity in the plane and orthogonal to the first direction.

24. The gyroscope of claim 18, the at least one center proof-mass of the first guided mass system and the at least one center proof-mass of the second guided mass system rotate anti-phase about their respective sense axis in response to angular velocity about an axis in the plane and parallel the first direction.

25. A gyroscope comprising:

a substrate;

a guided mass system, the guided mass system comprising at least one first and second proof-masses, at least one center proof-mass, and at least one guiding arm,

wherein the at least one first, second and center proof-masses, and the at least one guiding arm are disposed parallel to the substrate,

wherein the at least one first proof-mass is coupled to the at least one guiding arm,

wherein the at least one second proof-mass is coupled to the at least one first proof-mass,

wherein the at least one center proof-mass is coupled to the at least one proof-mass and coupled to the substrate,

wherein the at least one guiding arm is coupled to the substrate;

an actuator for vibrating the guided mass system,

wherein the at least one guiding arm rotates in plane and allows motion of the at least one first and second proof-masses along a first direction in a plane parallel to the substrate,

wherein the at least one center proof-mass rotates about an axis normal to the plane,

wherein the at least one guiding arm and the at least one first and second proof-masses rotate about a first sense axis in response to the angular velocity about a first input axis that is in the plane and orthogonal to the first direction, the first sense axis being in-plane and parallel to the first direction;

wherein the at least one center proof-mass rotates about an axis in plane and orthogonal to the first direction in response to the angular velocity about the second input axis that is in the plane and parallel to the first direction,

wherein the at least one second proof-mass is able to move in-plane in a direction orthogonal to the first direction in response to the angular velocity about a third input axis normal to the plane;

a first transducer for sensing motion of a portion of the at least one first proof-mass in response to the angular velocity about the first input axis;

a second transducer for sensing motion of a portion of the guided mass system in response to the angular velocity about the second input axis; and

a third transducer for detecting motion of a portion of the guided mass system in response to the angular velocity about the third input axis.

26. The device of claim 25, the at least one center proof-mass is coupled to the substrate by a lever arm, wherein the actuator causes the lever arm to rotate about an axis orthogonal to the plane, and wherein the lever arm rotates about an axis in the plane and orthogonal to the first direction in response to the angular velocity about the second input axis that is in the plane and parallel to the first direction.