金属环封装低频光纤布拉格光栅振动传感系统研制

研制了一种金属环封装的单柱体芯轴式光纤布拉格光栅(FBG)振动传感器,搭建了基于非平衡迈克耳逊干涉仪相位载波调制(PGC)解调技术的FBG振动传感器解调系统,实现了低频振动信号的高精度实时解调,并分析了各参数对传感器谐振频率和灵敏度等特性的影响。实验结果表明,研制的FBG振动传感器谐振频率为388Hz,在10～200Hz频率范围内,传感器的加速度灵敏度约为81pm/g,且加速度响应平坦,起伏小于1dB,与理论分析结果基本一致。研制的振动传感器可实现200Hz以下低频振动信号的实时检测,解调系统的波长检测精度为1.07×10-3 pm,最小可检测加速度为1.3×10-5 g。

Development of a metal annulus-based low frequency fiber Bragg grating vibration sensing system

A metal annulus-based single cylinder mandrel structure fiber Bragg grating(FBG) vibration sensor and a phase generated carrier(PGC) demodulator based on an unbalanced Michelson interferometer are proposed in this paper.The high precision and real time signal detection are achieved for this FBG vibration sensor.Experimental results show that its resonance frequency is 388 Hz and its acceleration sensitivity is around 81 pm/g over the frequency range from 10 Hz to 200 Hz,with fluctuation at different frequencies less than 1 dB.This FBG vibration sensor is suitable for monitoring vibration signals below the frequency of 200Hz.The wavelength resolution of the demodulation system is 1.07×10-3 pm,and the acceleration resolution of the sensing system is 1.3×10-5 g.