改进小波阈值去噪方法处理FBG传感信号

Processing of FBG sensor signal with improved wavelet threshold de-noising method

为了精确获得光纤布拉格光栅（FBG）传感系统的波长漂移，通过分析传统阈值和阈值函数存在的不足，提出改进阈值选取策略，并构建一种新的阈值函数处理FBG信号；小波基和分解尺度的合理选取提升小波去噪性能，本文提出确定小波基和分解尺度的方法；仿真与实验结果表明，与传统软硬阈值方法相比，本文所提方法信噪比（SNR）提升2～4dB；与本文文献所提方法相比，信噪比提高了1．5dB。满足精确解调FBG中心波长的需要。

In order to gain the wavelength of fiber Bragg grating sensor system precisely, by analyzing the shortcoming of traditional methods,an improved threshold selection strategy is proposed, and a new threshold function is built to deal with FBG signal. The reasonable selection of wavelet basis and decomposition scale can improve the performance of de-noising. A method is put forward about wavelet basis and decomposition scale. The result of simulation and ex- periment show that the signal noise ratio（SNR） can increase by 2dB to 4dB compared with the traditional soft thresh- old and hard threshold method. While compared with the reference method, the SNR improves 1.5dB. This method can meet the need of precise demodulation FBG wavelength.