Fiber grating temperature/vibration/strain composite sensor and working method thereof

Abstract

A fiber bragg grating temperature / vibration / strain composite sensor and a working method thereof are provided. The fiber bragg grating temperature / vibration / strain composite sensor comprises a first base and a second base, the opposite ends of the first base and the second base are respectively provided with a first supporting beam and a second supporting beam, and a spring beam is arranged between the first supporting beam and the second supporting beam. An L-cantilever beam is arranged in the center of the second base, an optical fiber is pasted in a groove in the top of the sensor, and a first fiber grating and a second fiber grating are separately engraved in the suspended position of the optical fiber. When the vibration is measured, the L-cantilever beam generates the forced vibration and acts on the second fiber bragg grating, and the vibration and temperature signals are obtained by performing fast Fourier transform on the output signal of the second fiber bragg grating; and when the strain is measured, the first fiber bragg grating is compressed or stretched under the action of the strain, and the output signal of the first fiber bragg grating is measured to obtain a strain signal, and meanwhile, the temperature measured by the fiber bragg grating is used for performing temperature compensation on the strain signal. The sensor has the advantages of being simple in structure and high in sensitivity and measurement precision, and being practical and efficient.

Description

technical field [0001] The invention relates to a compound sensor, in particular to a fiber grating temperature / vibration / strain compound sensor and its working method. Background technique [0002] As an optical sensor, fiber optic sensor is widely used in the measurement of physical quantities, such as the measurement of physical and chemical parameters such as temperature, vibration, stress, strain, pressure and concentration of chemical solvents. Optical fiber sensors have the advantages of high sensitivity, anti-electromagnetic interference, and anti-corrosion. In addition, as a kind of fiber optic sensor, fiber grating also has the advantages of small size, light weight, slender and soft, easy to make a simple sensor structure, easy to realize distributed measurement, etc., and has important applications in many engineering fields . [0003] Taking large-scale energy systems as an example, there are often factors such as large temperature differences and strong inter...

AI Technical Summary

Problems solved by technology

Therefore, when using traditional piezoelectric and piezoresistive sensors, it is necessary to design a special packaging structure to ensure that the sensor can work normally, while the fiber grating sensor has strong anti-electrical interference and corrosion resistance, and does not require a special packaging structure when used, so it can Further realize the miniaturization and integration of sensors, and realize reliable and real-time data monitoring of energy systems; existing fiber optic sensors are mainly based on single parameter measurement, and there are few researches on composite fiber optic sensors, and for fiber optic vibration sensors, most The sensor has a larger mass, or has a lower resonance frequency, which is not conducive to the measurement of vibration

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