基于聚合物封装的光纤布拉格光栅压力传感器

FBG pressure sensor based on polymer packaging

设计并研究了一种光纤布拉格光栅压力传感器,FBG1与FBG2串联连接,其中FBG1直接封装于聚合物之中,而FBG2先粘贴于弹性基体上再封装于聚合物之中。推导了传感器的灵敏度和解耦算法,并且使用有限元法计算了本传感器压力灵敏度和温度灵敏度,最后对传感器进行了实验验证。实验结果表明FBG1和FBG2的压力灵敏度分别为197.4 pm/MPa和95.7 pm/MPa,温度灵敏度分别为47.2 pm/℃和36 pm/℃,具有良好的线性度,较小的回程误差,并且符合该传感器感知的压力和温度解耦条件。同时,随着聚合物小圆环直径增加,基体的应变量越来越大,并趋近于没有基体时聚合物的应变量。研究表明,较之传统的聚合物封装的光纤光栅压力传感器,本传感器的聚合物与套筒不易脱落,两者之间的非固结连接可以增加传感器灵敏度,并且本传感器具有温度补偿功能。

An FBG sensor was designed and studied.FBG1 and FBG2 were connected in series;FBG1 was directly encapsulated in the polymer,and FBG2 was pasted on anelastic substrate and then encapsulated in the polymer.The sensitivity of the sensor and the decoupling algorithm were theoretically deduced,and the pressure sensitivity and temperature sensitivity of the sensor were calculated with finite element method.Finally,the sensorwas tested in experiments.Experiment results show that the pressure sensitivities of FBG1 and FBG2 are 1 97.4pm/MPa and 95.7pm/MPa,respectively,their temperature sensitivitiesare 47.2pm/℃ and 36 pm/℃,respectively with good linearity and low hysteresis error.Meanwhile,the test result meets the decoupling condition between pressure and temperature of the sensor.As the diameter of the small polymer ring increases the strain value of the substrate material is getting larger and larger,and tends to the strain value of the polymer without the substrate material.The study shows that compared with conventional FBG pressure sensor based on polymer packaging,the polymer of the sensor is not easy to fall off from the sleeve;and due to the unconsolidated attaching between thepolymer and sleeve the sensitivity of the sensor is increased;in addition the sensor also has temperature compensation function.