一种高频双FBG加速度传感器及其解调方法

为了适应光纤传感器在高转速机械设备安全监测 中的应用,设计了一种双光纤布拉格光栅(FBG)对称式 的高频光纤光栅加速度传感器,并提出一种新的匹配FBG解调方法。阐述了传感器 的结构和工作原理,利用有限元方法分析了传感器的静态与动态特性,并通过实验对传感 器的灵敏度、幅频响应特性和横向 抗干扰能力等方面进行了测试。提出了基于比值法的匹配光纤光栅解调原理,消除了光源不 稳定 等因素对检测精度的影响。实验结果表明,本文传感器谐振频率为900Hz,灵敏度为88mV/g,加速度测量 范围大于80m/s²,横向 灵敏度系数小于10%,并具备较好的抗干扰能力。

A high-frequency dual-FBG accelerometer and its demodulation method

In order to adapt to the application of optical fiber sensor in high s peed mechanical equipment safety monitoring,a kind of double-fiber-Bragg-grating (FBG) symmetrical high-frequ ency acceleration sensor is designed and a novel FBG matched demodulation method is proposed.The structure and working principle of sensor are demonstrated,and the theoretical calculation and finite e lement method are used to analyze static and dynamic characteristics of the sensor.Finally the sensitivity,the amplitude-f requency response characteristics and transverse anti-jamming ability of the accelerometer are tested experimentally. The matched FBG demodulation principle based on the ratio method is analyzed,which can eliminate the impact o f the LED instability on the measurement accuracy.The experimental results show that:the sensor resonant fr equency is 900Hz,the sensitivity is 88mV/g and the measurement value of acceleration is up to 80m/s ², which is basically consistent with the theoretical calculation and finite elemen t analysis results;the transverse sensitivity coefficient is less than 10%,and the sensor has a good anti-interference ability.