激光与光电子学进展, 2020, 57 (17): 170602, 网络出版: 2020-09-01
分布式拉曼光纤温度传感器的误差修正方法 下载: 1442次
Error Correction Method for Distributed Fiber Raman Temperature Sensor
光纤光学 分布式光纤温度传感器 光纤损耗 光纤色散 系统波动 linear插值算法 fiber optics distributed fiber temperature sensor fiber loss fiber dispersion system fluctuation linear interpolation algorithm
摘要
为了提高基于拉曼散射分布式光纤温度传感器的测量准确度和稳定性,提出了一种自动补偿光纤损耗、光纤色散和系统波动的温度解调方法,并进行实验验证。通过采样值对Stokes和Anti-Stokes散射光的损耗系数进行实时计算,并对二者的差异进行动态补偿,弥补了温度测温准确度随光纤长度增加而下降的缺点。采用linear插值算法对因光纤色散效应导致Stokes和Anti-Stokes背向散射光信号的错位进行修正,消除了升温处两侧因色散导致的温度异常点,提高了温度测量准确度。最后根据采样值和环境温度值对系统的波动性进行修正,减小了温度解调值波动范围。实验结果表明:经过修正后的系统在8 km处温度的测量误差范围从-2.72%~7.24%缩小为-0.34%~1.04%,整条光纤的温度波动性从-0.0128~1.6181 ℃下降为-0.8991~ 0.6476 ℃。
Abstract
To improve the measurement accuracy and measurement stability of the distributed fiber Raman temperature measurement system, a temperature demodulation method that self-compensates for fiber loss, fiber dispersion, and system fluctuation was presented and experimentally verified. The loss coefficient between the Stokes and Anti-Stokes backscatter signals was calculated in real time by sampling value, and the difference between them was dynamically corrected. This prevents the temperature accuracy from decreasing as the fiber length increases. A linear interpolation algorithm was used to correct the misalignment of the Stokes and anti-Stokes backscatter signals due to the dispersion effect of the optical fiber, eliminating temperature anomaly points caused by dispersion on both sides of the heating point, thus improving temperature measurement accuracy. Finally, the fluctuation of the system was corrected according to the sampling value and the environmental temperature value. Thus, the fluctuation range of the temperature demodulation value was reduced. Experimental results indicated that the error range of temperature measurement decreased from -2.72-7.24% to -0.34-1.04% when the fiber distance was 8 km. Temperature fluctuations were reduced from -0.0128-1.6181 ℃ to -0.8991-0.6476 ℃ across the fiber.
王青山, 王伟杰, 郭旭, 毛丽娜, 牧继清, 陈磊. 分布式拉曼光纤温度传感器的误差修正方法[J]. 激光与光电子学进展, 2020, 57(17): 170602. Qingshan Wang, Weijie Wang, Xu Guo, Lina Mao, Jiqing Mu, Lei Chen. Error Correction Method for Distributed Fiber Raman Temperature Sensor[J]. Laser & Optoelectronics Progress, 2020, 57(17): 170602.