论文部分内容阅读
针对传统的基于相位敏感光时域反射计(-OTDR)的分布式振动传感系统在对外界振动信号降噪效果方面的不足,提出了一种基于小波包的降噪优化方法:首先分析采集到振动点处信号的特征并选取最优基波Sym6,比对不同的基波分解层数对于原始信号降噪处理后的效果,从中选择三层分解作为最优化分解层数。其次对信号处理前后的信号进行傅里叶变换,通过频域比对证明小波包降噪方法能够有效去除主振信号以外的噪声。再次针对振动点附近的采集点进行了频谱分析,结果显示只有振动点对应采集点的频率与振动频率相同,从而证明了系统实际空间分辨率可达到1 m。
In order to overcome the shortcomings of traditional vibration sensing system based on phase-sensitive optical time-domain reflectometer (-OTDR), this paper proposes a noise reduction optimization method based on wavelet packet. Firstly, The characteristics of the signal at the vibration point are collected and the optimal fundamental Sym6 is selected to compare the effect of different decomposition levels of the fundamental wave on the noise reduction of the original signal. Three layers of decomposition are selected as the optimal decomposition layers. Secondly, the signals before and after the signal processing are Fourier transformed, and the wavelet packet denoising method is proved to be effective in removing noise other than the main vibration signal by frequency domain comparison. Spectrum analysis of the collection point near the vibration point again shows that only the frequency and vibration frequency of the collection point corresponding to the vibration point are the same, which proves that the actual spatial resolution of the system can reach 1 m.