High dynamic range gyroscope

• US 10,697,772 B1
• Filed: 02/15/2019
• Issued: 06/30/2020
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Sorenson, Logan D., Perahia, Raviv, Chang, David T., Kubena, Randall L., Kirby, Deborah J., Nguyen, Hung, Joyce, Richard J.
• Primary Examiner(s): Cordero, Lina M
• Application Number:
  US16/277,610
• Time in Patent Office: 501 Days
• Field of Search: None
• CPC Class Codes: G01C 19/5684 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5726 Signal processing
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• CPC Class Codes: H03G 3/20 Automatic control H03G3/005 takes precedence; combined with volume compression or expansion H03G7/00
• CPC Class Codes: H03L 7/26 using energy levels of molecules, atoms, or subatomic particles as a frequency reference

Abstract

A sensor includes an acceleration or magnetic field sensitive microelectromechanical systems (MEMS) resonator, configured to oscillate in at least a first normal mode and a second normal mode. The sensor further includes: a coarse readout circuit configured to drive the first normal mode, measure a motion of the first normal mode, and derive from the measured motion a coarse measurement of the true acceleration or true external magnetic field; and a fine readout circuit configured to drive the second normal mode, measure a motion of the second normal mode, and derive from the measured motion and the coarse measurement a measurement of the difference between the true acceleration or true external magnetic field and the coarse measurement.

Claims

1. A sensor comprising:

an acceleration or magnetic field sensitive microelectromechanical systems (MEMS) resonator, configured to oscillate in at least a first normal mode and a second normal mode,

a coarse readout circuit configured to;

drive the first normal mode,

measure a motion of the first normal mode, and

derive from the measured motion of the first normal mode a coarse measurement of a true acceleration or true external magnetic field; and

a fine readout circuit configured to;

drive the second normal mode,

measure a motion of the second normal mode, and

derive from the measured motion of the second normal mode and the coarse measurement a fine measurement of a difference between the true acceleration or true external magnetic field and the coarse measurement.

2. The sensor of claim 1, wherein the coarse readout circuit is configured to generate the coarse measurement of the true acceleration or true external magnetic field of the MEMS resonator and the coarse measurement with a resolution of 19 bits.

3. The sensor of claim 2, wherein the fine readout circuit is configured to generate the fine measurement of the difference between the true acceleration or true external magnetic field of the MEMS resonator and the coarse measurement with a resolution of 19 bits.

4. The sensor of claim 1, wherein the first normal mode has a mode number of 2 and the second normal mode has a mode number of 3.

5. The sensor of claim 1, further comprising a mechanical tilt stage with two rotational degrees of freedom,

wherein:

the MEMS resonator is secured to the tilt stage, and

the coarse readout circuit is configured to generate a control signal proportional to the coarse measurement of the true external field of the MEMS resonator and apply the control signal to the mechanical tilt stage to reduce a rotation of the tilt stage.