Fiber-optic sensors in a rosette or rosette-like pattern for structure monitoring

• US 10,209,060 B1
• Filed: 03/14/2017
• Issued: 02/19/2019
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: VeraPhotonics, Inc.
• Original Assignee: Isensecloud, Inc.
• Inventors: Nguyen, An-Dien
• Primary Examiner(s): Stafira, Michael P
• Application Number:
  US15/458,311
• Time in Patent Office: 707 Days
• CPC Class Codes: G01B 11/165 by means of a grating deformed by the object
• CPC Class Codes: G01B 11/18 using photoelastic elements
• CPC Class Codes: G01D 5/35316 using a Bragg gratings
• CPC Class Codes: G01M 11/085 the optical fiber being on or near the surface of the DUT
• CPC Class Codes: G01M 5/0041 by determining deflection or stress
• CPC Class Codes: G01M 5/0091 by using electromagnetic excitation or detection
• CPC Class Codes: H01S 5/0617 using memorised or pre-programmed laser characteristics
• CPC Class Codes: H01S 5/06804 by monitoring an external parameter, e.g. temperature
• CPC Class Codes: H01S 5/06808 by monitoring the electrical laser parameters, e.g. voltage or current
• CPC Class Codes: H01S 5/12 the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength

Abstract

An apparatus, and related method, relates generally to a fiber-optic sensing system. In such a system, fiber-optic sensors are in a rosette or rosette-like pattern. An optical circulator is coupled to receive a light signal from a broadband light source, to provide the light signal to the fiber-optic sensors, and to receive a returned optical signal from the fiber-optic sensors. A spectral engine is coupled to the optical circulator to receive the returned optical signal and configured to provide an output signal.

Claims

1. A fiber-optic sensing system, comprising:

fiber-optic sensors of corresponding optical fibers in a rosette or rosette-like pattern;

a broadband light source of a Fiber Bragg Grating analyzer for having Fiber Bragg Grating wavelengths in the rosette or rosette-like pattern in parallel;

an optical circulator of the Fiber Bragg Grating analyzer coupled to receive a light signal from the broadband light source, to provide the light signal to the fiber-optic sensors, and to receive a returned optical signal from the fiber-optic sensors; and

a spectral engine of the Fiber Bragg Grating analyzer coupled to the optical circulator to receive the returned optical signal and configured to provide an output signal.

2. The fiber-optic sensing system according to claim 1, further comprising a network interface coupled to receive the output signal for communication of the output signal to a network.

3. The fiber-optic sensing system according to claim 1, wherein the spectral engine comprises a spectral element and an array detector.

4. The fiber-optic sensing system according to claim 1, wherein:

the broadband light source comprises super-luminescent light-emitting diodes; and

the fiber-optic sensors comprises at least two Fiber Bragg grating sensors disposed in the rosette or rosette-like pattern.

5. The fiber-optic sensing system according to claim 4, wherein the rosette or rosette-like pattern includes a directionally normal x-axis positioned first Fiber Bragg grating sensor and a directionally normal y-axis positioned second Fiber Bragg grating sensor respectively of different ones of the optical fibers.

6. The fiber-optic sensing system according to claim 4, wherein the rosette or rosette-like pattern includes a directionally normal x-axis positioned first Fiber Bragg grating sensor, a directionally normal y-axis positioned second Fiber Bragg grating sensor, and an x-y positioned third Fiber Bragg grating sensor respectively of different ones of the optical fibers.

7. The fiber-optic sensing system according to claim 4, wherein the rosette or rosette-like pattern includes at least one first Fiber Bragg grating sensor having either a directionally normal x-axis position or a directionally normal y-axis position and a second Fiber Bragg grating sensor having an x-y position respectively of different ones of the optical fibers.

8. The fiber-optic sensing system according to claim 4, wherein the rosette or rosette-like pattern includes three linearly independent fiber grating sensor arrays respectively of different ones of the optical fibers positioned for measuring components of plane strain including two normal strains ε

_x and ε

_y and shear strain ε

_xy.

9. The fiber-optic sensing system according to claim 8, further comprising a fourth fiber grating sensor array of another corresponding one of the optical fibers positioned for measuring temperature.

10. A fiber-optic strain system comprising the fiber-optic sensing system according to claim 1, the fiber-optic strain system further comprising a system-on-chip module coupled to receive the output signal and configured to clean up the output signal, detect peaks in the output signal, and quantify spectral power associated with each of the peaks detected.

11. The fiber-optic strain system according to claim 10, wherein the system-on-chip module is configured to quantify wavelength shifts in the output signal as being directly proportional to amounts of strain and spectral power sensed by each of the fiber-optic sensors in the rosette or rosette-like pattern.

12. A method for sensing, comprising:

attaching fiber-optic sensors of separate optical fibers in a rosette or rosette-like pattern to a structure;

generating a light signal with a broadband light source of a Fiber Bragg Grating analyzer for having Fiber Bragg Grating wavelengths in the rosette or rosette-like pattern in parallel;

receiving the light signal by an optical circulator of the Fiber Bragg Grating analyzer;

providing the light signal from the optical circulator to the fiber-optic sensors;

receiving a returned optical signal from the fiber-optic sensors by the optical circulator; and

providing the returned optical signal from the optical circulator to a spectral engine of the Fiber Bragg Grating analyzer to provide an output signal.

13. The method according to claim 12, further comprising:

preprocessing raw data at an edge node having the broadband light source to provide the output signal;

packetizing the output signal by a network interface; and

communicating the output signal to a network for Cloud storage and analytics processing.

14. The method according to claim 12, further comprising:

detecting logistics information with at least one logistics sensor coupled to a controller to provide logistics information associated with the output signal;

obtaining wavelength adjustment information responsive to the output signal and the logistics information for at least one fiber-optic sensor of the fiber-optic sensors in the rosette or rosette-like pattern; and

shifting a wavelength of a laser light source responsive to the wavelength adjustment information.

15. The method according to claim 12, wherein the returned optical signal comprises peaks associated with plane strain obtained by at least one first Fiber Bragg grating sensor of the fiber-optic sensors having either a directionally normal x-axis position or a directionally normal y-axis position and by a second Fiber Bragg grating sensor of the fiber-optic sensors having an x-y position respectively of different ones of the optical fibers.