光纤光栅压力传感器的理论建模及实验研究

Theoretical modeling and experimental study on optical fiber grating pressure sensor

鉴于压力传感器为工业生产中压力监控的一种必不可少的设备,分析了光纤光栅中心波长与光纤光栅应变之间的关系,阐述了带有硬中心的圆形膜片受到均匀压之后,膜片中心的挠度与压力之间的数学关系。在此基础上设计了圆形膜片作为流体压力转化光纤光栅敏感物理量的元件,并结合辅助元件完成对光纤光栅传感器组装,建立了传感器输入输出之间的线性数学模型。通过实验验证传感器线性度和重复性,运用数学计算得出了光纤光栅压力传感器各项参数,灵敏度Km=-0.658nm/MPa,初始波长λ0=1 578.441nm,为后期传感器稳定性作好了铺垫。

Pressure sensor is a key element for pressure supervising during industrial production.The mathematical relations between the central wavelength and the strain of optical fiber grating were analyzed.The mathematical relations between the deflection of central diaphragm and the pressure were analyzed when the circular flat diaphragm with rigid center was in uniform compression.A circular flat diaphragm was designed as the sensing element of fluid pressure and the converter to transfer the fluid pressure to optical fiber grating.The optical grating sensor was assembled with secondary element and the linear mathematical model of the input and output of the sensor was built.The linearity and repeatability of the sensor were demonstrated by experiments.The parameters of the optical fiber grating pressure sensor were got using mathematical computing.The sensitivity of the optical fiber grating pressure sensor is-0.658nm/MPa,and the initial wavelength is 1 578.441 nm.This research paves the way for the further stability of the sensor.