基于光纤光栅的一体式靶式流量传感技术

针对以往液压系统检测中存在的特点,如结构杂、体积大、精度低,设计了一种基于光纤布拉格光栅(FBG)的一体式靶式流量传感器。分析了FBG及靶式流量传感原理,设计出一种组成紧凑、便于密封以及拆装的一体式靶片,将放在流体里的靶片受到的与流速成相关变化的冲击力变为FBG波长的漂移,双FBG对称分布,分别放在悬臂梁两表面中轴线处,这种差动形式可以很好地增加灵敏度,并且可以解决应变和温度的交叉敏感现象。通过FLUENT分析了流体形式,结果显示这种结构给流体造成的影响比一般结构小。实验测试过程中,双FBG中心波长总变化数值和放置于靶片的质量呈现出明显的线性变化,并且灵敏度为一个FBG灵敏度的双倍,可靠性以及稳定性较好。

One-piece Flow Target Type Based on Fiber Bragg Grating Sensing Technology

Aiming at the problems existing in traditional hydraulic system detection,such as low measuring accuracy,large size and complex structure,a kind of integrated target flow sensor based on fiber Bragg grating(FBG)was designed.This paper analyzed the principle of FBG and target type flow sensing,and designed an integrated target with a compact composition,which was easy to seal and disassemble.Double FBG symmetrical distribution was respectively placed on the central axis of the two surfaces of the cantilever beam.This differential form can increase the sensitivity well and solve the cross-sensitivity phenomenon of strain and temperature.Through the simulation analysis of fluid state by FLUENT software,it is concluded that the integrated target structure has less influence on fluid state than the traditional structure.In the hydraulic experiment,there is a good linear relationship between the change amount of the center wavelength of double FBG and the mass loaded on the target,and the sensitivity is twice as high as that of a single FBG,with good stability and reliability.