基于L型悬臂梁的光纤光栅加速度传感器

Fiber Bragg grating accelerometer based on L-shaped cantilever beam

为了测量低频小信号,提出了一种基于L型悬臂梁的光纤光栅(FBG)加速度传感器,并进行了理论分析,推导出了其灵敏度及谐振频率表达公式。为了得出结构的最优参数,根据理论公式进行了仿真分析得出仿真曲线。根据仿真曲线,选定传感器各个参数,制作出传感器实物,分别对传感器灵敏度幅频响应,线性响应及横向抗干扰性进行了实验测试,实验测试出传感器谐振频率280 Hz,在充装硅油阻尼后测量带宽为1 Hz-240 Hz,测量带宽内响应曲线平坦度在±1.5 dB以内,灵敏度可达到52 pm/g,线性相关性为99.97%,与理论谐振频率290 Hz,灵敏度59 pm/g较吻合,表明了理论分析的正确性,同时传感器具有较好的横向抗干扰性,横向抗干扰性为4.2%,研究表明此传感器可以应用于低频小信号场合的振动测试。

In order to measure low-frequency and small signals,a fiber grating(FBG)acceleration sensor based on an L-shaped cantilever beam is proposed,and theoretical analysis is carried out,and its sensitivity and resonance frequency expression formula are deduced.In order to obtain the optimal parameters of the structure,a simulation analysis was carried out according to the theoretical formula and the simulation curve was obtained.According to the simulation curve,the various parameters of the sensor were selected,and the actual sensor was produced,and the sensor sensitivity amplitude-frequency response,linear response and lateral anti-interference performance were tested respectively.The experimental test shows that the sensor resonance frequency was 280 Hz.After filling with silicone oil damping,the measurement bandwidth is 1 Hz-240 Hz,and the flatness is within±1.5 db in the response curve within the measurement bandwidth,the sensitivity can reach 52 pm/g,and the linear correlation is 99.97%,which is in good agreement with the theoretical resonance frequency of 290 Hz and the sensitivity of 59 pm/g,indicating the correctness of the theoretical analysis.At the same time,the sensor has a good lateral anti-interference performance,which is 4.2%.Research shows that this sensor can be applied to vibration test in low frequency and small signal occasions.