Feng Zhiyu, Cheng Yu, Chen Ming, Yuan Libo, Hong Deng, Li Litong
State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Yangtze Optical Fiber and Cable Joint Stock Limited Company, Wuhan 430073, China.
College of Photonic and Electronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
Sensors (Basel). 2022 May 24;22(11):3970. doi: 10.3390/s22113970.
We proposed a novel temperature-compensated multi-point strain sensing system based on cascaded FBG and optical FMCW interferometry. The former is used for simultaneous sensing of temperature and strain, and the latter is used for position information reading and multiplexing. In the experiment, a narrow linewidth laser with continuous frequency-sweeping was used as the light source. After demodulating the beat-frequency signal, the link information of the 16 m fiber was obtained, and the measured result was identical to the actual position. The measurement accuracy reached 50.15 mm, and the dynamic range was up to 22.68 dB. Meanwhile, we completed the sensing experiments for temperature range from 20 °C to 90 °C and strain range from 0 με to 7000 με. The sensitivity of the sensing system to temperature was 10.21 pm/°C, the sensitivity and accuracy to strain were as high as 1.163 pm/με and 10 με, respectively. Finally, the measured strain and temperature values were obtained using the sensing matrix. The sensing system has important practical significance in the field of quasi-distributed strain measurement.
我们提出了一种基于级联光纤布拉格光栅（FBG）和光学调频连续波（FMCW）干涉测量的新型温度补偿多点应变传感系统。前者用于同时感测温度和应变，后者用于位置信息读取和复用。在实验中，使用具有连续扫频的窄线宽激光器作为光源。在解调拍频信号后，获得了16米光纤的链路信息，测量结果与实际位置一致。测量精度达到50.15毫米，动态范围高达22.68分贝。同时，我们完成了温度范围从20℃至90℃以及应变范围从0微应变至7000微应变的传感实验。传感系统对温度的灵敏度为10.21皮米/℃，对应变的灵敏度和精度分别高达1.163皮米/微应变和10微应变。最后，使用传感矩阵获得了测量的应变和温度值。该传感系统在准分布式应变测量领域具有重要的实际意义。
