Accelerometer system enclosing gas

Patent metadata

Field	Value
Publication number	US-11079227-B2
Application number	US-201916371657-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 1, 2019
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

This disclosure is related to devices, systems, and techniques for determining, using an electro-opto-mechanical accelerometer system, a frequency value in order to determine an acceleration value. For example, an accelerometer system includes a light-emitting device configured to emit an optical signal and a circuit. The circuit is configured to determine a frequency value corresponding to the optical signal and determine an acceleration value based on the frequency value. Additionally, the accelerometer system includes a housing that encloses the light-emitting device, the circuit, and Helium gas, where the Helium gas defines a partial pressure within a range between 0.1 torr and 760 torr.

First claim

What is claimed is:

1. An accelerometer system comprising:
a light-emitting device configured to emit an optical signal;
a circuit configured to:
modulate, using a modulating device, the optical signal to produce a modulated optical signal;
receive, using a photoreceiver, the modulated optical signal;
convert, using the photoreceiver, the modulated optical signal into an electrical signal;
process the electrical signal to obtain a processed electrical signal;
transmit the processed electrical signal to the modulating device, wherein the modulating device is configured to modulate the optical signal based on the processed electrical signal;
determine, based on the first processed electrical signal, a frequency value; and
determine an acceleration value based on the frequency value; and

a housing that encloses the light-emitting device, the circuit, and Helium gas, wherein the Helium gas defines a partial pressure within a range between 0.1 torr and 760 torr.

2. The accelerometer system of claim 1 , wherein the housing comprises a crystalline material, the crystalline material preventing the Helium gas from escaping the housing.

3. The accelerometer system of claim 2 , wherein the material comprises silicon.

4. The accelerometer system of claim 1 , wherein the housing comprises:
a first layer comprising an amorphous solid material; and
a second layer comprising a crystalline material, the crystalline material preventing the Helium gas from escaping the housing.

5. The accelerometer system of claim 1 , further comprising:
a first double-ended tuning fork (DETF) structure;
a second DETF structure;
one or more tethers;
a frame; and
a proof mass suspended within the frame by the first DETF structure, the second DETF structure, and the one or more tethers,
wherein the proof mass is suspended in a first direction relative to the frame by the first DETF structure and the second DETF structure,
wherein the first DETF structure contacts a first side of the proof mass and the second DETF structure contacts a second side of the proof mass, the first side being opposite the second side, and
wherein the proof mass is suspended in a second direction and a third direction relative to the frame by the one or more tethers.

6. The accelerometer system of claim 5 , wherein the first direction, the second direction, and the third direction represent three axes (x-axis, y-axis, and z-axis) of a three-dimensional Cartesian space.

7. The accelerometer system of claim 5 , wherein the first DETF structure and the second DETF structure each comprise:
two or more photonic crystal mechanical beams with a gap between the two or more photonic crystal mechanical beams.

8. The accelerometer system of claim 5 , wherein a mechanical quality factor associated with the first DETF structure and the second DETF structure is within a range between 5,000 and 2,000,000.

9. The accelerometer system of claim 1 wherein the light-emitting device emits the optical signal at a power value, wherein the power value is within a range between 1 nanowatt (nW) and 10,000 nW.

10. The accelerometer system of claim 1 , wherein the modulating device is a first modulating device, the photoreceiver is a first photoreceiver, the modulated optical signal is a first modulated optical signal, the electrical signal is a first electrical signal, the processed electrical signal is a first processed electrical signal, the frequency value is a first frequency value, and wherein the circuit is further configured to:
modulate, using a second modulating device, the optical signal to produce a second modulated optical signal;
receive, using a second photoreceiver, the second modulated optical signal;
convert, using the second photoreceiver, the second modulated optical signal into a second electrical signal;
process the second electrical signal to obtain a second processed electrical signal;
transmit the second processed electrical signal to the second modulating device, wherein the second modulating device is configured to modulate the optical signal based on the second processed electrical signal; and
determine, based on the second processed electrical signal, a second frequency value.

11. The accelerometer system of claim 10 , wherein the acceleration value is a first acceleration value, wherein to determine the first acceleration value, the circuit is configured to:
subtract a baseline frequency value from the first frequency value to obtain a first frequency difference value; and
determine, based on the first frequency difference value, a first acceleration value, and wherein to determine a second acceleration value, the circuit is configured to:
subtract a baseline frequency value from the second frequency value to obtain a second frequency difference value; and
determine, based on the second frequency difference value, a second acceleration value.

12. A method comprising:
emitting, using a light-emitting device, an optical signal;
modulating, using a first modulating device of a circuit, the optical signal to produce a first modulated optical signal;
receiving, using a first photoreceiver of the circuit, the first modulated optical signal;
converting, using the first photoreceiver, the first modulated optical signal into a first electrical signal;
processing the first electrical signal to obtain a first processed electrical signal;
transmitting the first processed electrical signal to the first modulating device, wherein the first modulating device is configured to modulate the optical signal based on the processed electrical signal; and
determining, based on the first processed electrical signal, a frequency value;
determining, using the circuit, an acceleration value based on the frequency value; and
enclosing, using a housing, the light-emitting device, the circuit, and Helium gas, wherein the Helium gas defines a partial pressure within a range between 0.1 torr and 760 torr.

13. The method of claim 12 , wherein the housing comprises a crystalline material, the crystalline material preventing the Helium gas from escaping the housing.

14. The method of claim 12 , wherein the housing comprises:
a first layer comprising an amorphous solid material; and
a second layer comprising a crystalline material, the crystalline material preventing the Helium gas from escaping the housing.

15. The method of claim 12 , further comprising:
suspending a proof mass suspended within a frame by a first DETF structure, a second DETF structure, and one or more tethers,
wherein the proof mass is suspended in a first direction relative to the frame by the first DETF structure and the second DETF structure,
wherein the first DETF structure contacts a first side of the proof mass and the second DETF structure contacts a second side of the proof mass, the first side being opposite the second side, and
wherein the proof mass is suspended in a second direction and a third direction relative to the frame by the one or more tethers.

16. The method of claim 12 , wherein the modulating device is a first modulating device, the photoreceiver is a first photoreceiver, the modulated optical signal is a first modulated optical signal, the electrical signal is a first electrical signal, the processed electrical signal is a first processed electrical signal, the frequency value is a first frequency value, and wherein the method further comprises:
modulating, using a second modulating device, the optical signal to produce a second modulated optical signal;
receiving, using a second photoreceiver, the second modulated optical s

Assignees

• Honeywell Int Inc

Inventors

• Fertig Chad
• Savchenko Arthur
• Tin Steven
• Krueger Neil
• Dorr Joshua

Classifications

• G01C19/5621

  the devices involving a micromechanical structure · CPC title

• G01P15/13

  by measuring the force required to restore a proofmass subjected to inertial forces to a null position · CPC title

• G01P15/18

  in two or more dimensions · CPC title

• G01P15/097

  by vibratory elements · CPC title

• G01P15/093 Primary

  by photoelectric pick-up · CPC title