大量程高灵敏度的光纤光栅低频振动传感器研究

Research on a fiber grating low frequency vibration sensor with large range and high sensitivity

针对低频振动检测的需求,研制了一种基于柔性铰链的光纤光栅(FBG)振动传感器,实现了在一定范围内对低频信号的高精度测量。根据传感器的理想结构模型,结合力矩平衡方程和拉格朗日方程给出了传感器的灵敏度和固有频率的计算方法,并采用ANSYS软件对传感器的结构进行有限元分析,得到了一阶谐振频率为92.457 Hz。通过性能测试试验,传感器在0.5~55 Hz这个频率范围内平坦度好,固有频率为91 Hz,与有限元分析结果一致,灵敏度为1.94 nm/g,线性度为99.99%。其纵向灵敏度远优于横向灵敏度,具备较强的横向抗干扰能力。

A fiber grating(FBG)vibration sensor based on a flexible hinge suitable for low-frequency vibration measurement was proposed,which realized high-precision measurement of low-frequency signals within a certain range in response to the needs of low-frequency vibration detection.According to the ideal structure model of the sensor,combined with the torque balance equation and the Lagrangian equation,the calculation method of the sensitivity and natural frequency of the sensor was given,and the structure of the sensor was analyzed by finite element using ANSYS software,and the first-order resonance frequency was obtained as 92.457 Hz.Through the performance test,the sensor has good flatness in the frequency range of 0.5 to 55 Hz,and the natural frequency is 91 Hz,which is consistent with the finite element analysis result.The sensitivity is 1.94 nm/g and the linearity is 99.99%.The longitudinal sensitivity is much better than the lateral sensitivity,and it has strong lateral anti-interference ability.