高精度调频连续波光纤压力传感器温度特性分析及补偿方法

Analysis and Compensation Method of Temperature Characteristics of High-Precision Frequency-Modulated Continuous Wave Fiber Optic Pressure Sensor

针对高精度调频连续波光纤压力传感器对温度和压力交叉敏感的问题.从理论和实验分析该压力传感器的温度特性.并通过优化设计压力传感器的结构,以及采用最小二乘法对温度进行实时补偿。经过理论计算可知,当温度从25℃到65℃变化时.温度对Fabry-Perot(F-P)腔腔长的形变量为1000μm。通过优化设计F-P腔,可以使温度对F-P腔的影响降至50μm。通过实验测试结构优化后的F-P腔腔长的形变量与温度的关系,并采用最小二乘法对温度进行实时补偿。温度补偿后,F-P腔腔长的形变量从50μm降至4.5μm,有效降低对温度敏感。提高调频连续波光纤压力传感测量的可靠性和实用性。

In view of cross sensitivity of the high-precision frequency-modulated continuous-wave fiber optic pressure sensor to temperature and pressure,the temperature characteristics of the pressure sensor are analyzed theoretically and experimentally. The structure of the pressure sensor is optimized,the effect of temperature on Fabry-Perot(F-P) cavity can be reduced to 50 μm. After theoretical calculations,it can be known when the temperature changes from 25 ℃ to 65 ℃,the deformation of the F-P cavity by the temperature is 1000 μm. By optimizing the F-P cavity design,the influence of temperature on the length of the F-P cavity can be effectively reduced. The relationship between the deformation of the cavity length of the optimized F-P cavity and the temperature is tested through experiments. The least-squares method is used for temperature compensation in realtime. After the temperature compensation,the deformation of the F-P cavity length is directly reduced from 50 to4. 5 μm,which reduces temperature cross-sensitivity,improves the reliability and practicability of high-precision frequency-modulated continuous-wave fiber optic pressure sensing measurement.