基于EEMD—小波阈值的分布式测温系统的研究

Research on distributed temperature measurement system based on EEMD-Wavelet threshold

在分布式拉曼测温系统中,所包含的温度信息的反斯托克斯光比较微弱,容易被噪声掩盖,且传统的去噪方法容易滤除掉系统的原始特征,因此针对上述问题,本文采用EEMD结合小波阈值降噪的去噪方法,在保留信息原始特征的情况下,极大的提高系统的信噪比(SNR)和系统的测温精度。仿真证明,该算法在1 dB的噪声下,信噪比提高了2.3 dB。实验结果表明,系统的测量精度提升了76.11%。通过单独的小波阈值降噪处理,系统在测温光纤的熔接点的温度曲线是1℃以上的波动范围,而通过该算法后,系统解调温度波动范围在0.5℃左右,最后通过实验证明该算法不影响系统的空间分辨率。

In distributed Raman temperature measuring system,the temperature of the contained information of anti stokes light is weak,easily masked by noise,and the traditional denoising method is easy to filter to remove the original characteristics of the system,thus aiming at these problems,this paper USES the EEMD combined with wavelet threshold denoising method to reduce the noise of engine,under the condition of retain the original information feature,Greatly improve the system′s signal to noise ratio(SNR)and temperature measurement accuracy.Simulation results show that the SNR of the algorithm is improved by 2.3 dB when the noise is 1 dB.Experimental results show that the measurement accuracy of the system is improved by 76.11%.Through a separate wavelet threshold de-noising process,the temperature curve of the fusion point of the optical fiber is more than 1℃fluctuation range,and the demodulation temperature fluctuation range of the system is about 0.5℃after the algorithm is adopted.Finally,the experiment proves that the algorithm does not affect the spatial resolution of the system.