Dual mode sensing for vibratory gyroscope

• US 8,020,441 B2
• Filed: 02/05/2008
• Issued: 09/20/2011
• Est. Priority Date: 02/05/2008
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Seeger, Joseph
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US12/026,490
• Publication Number:
  US 20090193892A1
• Time in Patent Office: 1,323 Days
• Field of Search: 735/041.2, 735/041.4, 735/041.5, 735/040.2, 735/040.4
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis

Abstract

An angular rate sensor is disclosed. The angular rate sensor comprises a substrate and a drive subsystem partially supported by a substrate. The drive subsystem includes at least one spring, at least one anchor, and at least one mass; the at least one mass of the drive subsystem is oscillated by at least one actuator along a first axis. Coriolis force acts on moving the drive subsystem along or around a second axis in response to angular velocity of the substrate around the third axis. The angular rate sensor also includes a sense subsystem partially supported by a substrate. The sense subsystem includes at least one spring, at least one anchor, and at least one mass.

Claims

1. An angular rate sensor comprising

a substrate;

a drive subsystem partially supported by the substrate with at least one spring, at least one anchor; and

at least one mass;

wherein the at least one mass of the drive subsystem is oscillated by at least one actuator along a first axis; and

Coriolis force acting on the drive subsystem along a second axis in response to angular velocity of the substrate around a third axis;

a sense subsystem partially supported by the substrate with at least one spring, at least one anchor; and

at least one mass;

wherein the sense subsystem moves along or around a fourth axis; and

motion of the sense subsystem can be sensed by a transducer and is proportional to the angular velocity of the substrate about the third axis; and

at least one flexible coupling between the drive subsystem and the sense subsystem, wherein the flexible coupling couples a drive subsystem motion in the second axis to the sense subsystem motion about the fourth axis, wherein the flexible coupling causes two resonant modes allowing both in-phase and anti-phase motion between the sensor subsystem and the drive subsystem.

2. The angular rate sensor of claim 1, wherein the drive subsystem, the sense subsystem and the flexible coupling form a mechanical system with at least two resonant modes, at least one drive subsystem anti-resonance and a least one sense subsystem anti-resonance.

3. The angular rate sensor of claim 2, wherein a frequency of drive oscillations along the first axis substantially matches drive anti-resonance frequency;

and a frequency of drive oscillations along the first axis substantially matches sense anti-resonance frequency.

4. The angular rate sensor of claim 1, where the drive subsystem comprises plurality of masses;

and plurality of springs;

wherein the at least one mass from the drive subsystem is flexibly coupled to the at least one mass from the sense subsystem.

5. The angular rate sensor of claim 1, where the sense subsystem comprises a plurality of masses;

and comprises plurality of springs;

wherein the at least one mass from the sense subsystem is flexibly coupled to the at least one mass from the drive subsystem.

6. The angular rate sensor of claim 1 comprising wherein the drive subsystem oscillates normal to a plane parallel to the substrate;

and the sense subsystem moves around an axis normal to the plane;

the sense subsystem responding to angular velocity along an axis parallel to the plane.

7. The angular rate sensor of claim 1 comprising wherein the drive subsystem oscillates in a plane parallel to the substrate;

and the sense subsystem moving around an axis normal to the plane;

the sense subsystem responding to angular velocity along an axis normal to the plane.