Optical fiber raster vibration sensor of tunable matching filtering demodulation

Abstract

The invented optical-fibre grating vibration sensor is characterized by that it utilizes a demodutation grating and a sensing grating and makes them be series-connected together, and respectively makes them be stuck on a main beam and an auxiliary beam, two beams are made of identical material and have identical heat expansion coefficient, so that their central wavelengths can be synchronously shifted with temperature, therefore they have automatic temperature compensation function so as to implement matching filter demodutation. Said invention utilizes the detection of light intensity change of sensing grating reflecting light to monitor the parameters of vibration frequency and vibration amplitude of monitored body, finally utilizes computer or single-chip computer to make analysis and processing of body vibration frequency spectrum.

Description

technical field [0001] The invention relates to a fiber grating vibration sensor capable of tunable matching filter demodulation, which is mainly used for measuring the vibration frequency and amplitude of an object and belongs to the field of optoelectronic testing. technical background [0002] Vibration sensors have important applications in many fields, for example, real-time monitoring of large electromechanical equipment, bridge structures, etc. The vibration sensor can judge the working state of the object by monitoring the vibration state of the object, and troubleshoot in time to avoid major accidents. [0003] Traditional electrical vibration sensors output weak electrical signals, which cannot be transmitted over long distances. Moreover, such sensors have poor reliability in outdoor harsh environments and are not suitable for use in long-term remote safety monitoring systems such as bridges. In addition, electrical sensors are susceptible to electromagnetic inte...

AI Technical Summary

Problems solved by technology

This kind of sensor has a narrow frequency response bandwidth and can only achieve vibration measurement of a specific resonant frequency

At the same time, this sensor structure only uses a fiber grating, which uses the principle of microbending loss instead of the wavelength demodulation principle of fiber grating. This sensor has a small signal-to-noise ratio, poor measurement accuracy, and low sensitivity.

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