Temperature self-compensation optical fiber/optical grating dynamic strain measurement method and system

Abstract

The invention relates to an automatic temperature compensated FBG dynamic strain measurement method and the system. The invention comprises a plurality of steps: adopt sensing Prague-FBG and filtering Prague-FBG as the match grating; control the central wavelength of the filtering Prague-FBG through the PID closed-loop control structure; when the FBGs central wavelength varies with the temperature, let the central wavelength of the filtering Prague-FBG vary with the central wavelength of the sensing Prague-FBG and keep a constant difference of the central wavelength of two FBGs; thus stabilize the static state of the measurement system which becomes self-adaptive to the environment temperature. The system comprises a broadband light source, a coupler, a sensing Prague-FBG, a filtering Prague-FBG, an electricity diode, a preamplifier, an A / D data converter, a computer, a plurality of electrostriction materials and a driving power for the electrostriction materials. The automatic temperature compensated FBG dynamic strain measurement method and the system has the advantages that reducing the technical requirements for making matching FBG and improving the temperature stability of the system; the automatic temperature compensated FBG dynamic strain measurement method can achieve the measurement of dynamic strain and temperature measurement points at the same time and can demodulate the high resonant frequency.

Description

technical field [0001] The invention relates to a method and system for measuring dynamic strain and vibration, in particular to a method and system for measuring dynamic strain of an optical fiber grating with automatic temperature compensation. Background technique [0002] Fiber Bragg Grating (FBG) sensor is considered to be the most promising fiber optic sensor in the 21st century. As a new type of fiber optic sensor, it not only has the advantages of fiber optic sensors, such as anti-electromagnetic interference, intrinsic safety, etc., but also has many unique features. Advantages: The wavelength modulation of the sensing information is not affected by the light intensity fluctuation of the light source and the line loss, the sensing repeatability and stability are good, and the networked measurement can be easily realized; its self-referencing feature enables it to achieve absolute measurement. [0003] Slowly varying parameter measurement and networked sensing techno...

AI Technical Summary

Problems solved by technology

This type of event is characterized by high frequency or short duration. Using the currently commonly used scanning demodulation methods, such as the F-P interferometer, the scanning frequency is only kilohertz, and demodulation of kilohertz and above cannot be achieved at all.

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