基于CEEMDAN-小波包的水下含伤信号去噪方法研究

Research on Denoising Method of Underwater Damaged Signal Based on CEEMDAN-wavelet Packet

针对水下含伤含噪信号的降噪问题,提出一种以CEEMDAN分解为基础的采取小波包分析综合降噪的新方法。该方法首先利用小波包去噪对初始的含噪信息进行预处理,借助CEEMDAN分解的方式得到多个特征模态分量,并通过自相关函数选择包含主导噪声的模态分量;然后采用渐进半软阈值对主导噪声的模态分量进行去噪,再通过信号重构得到最终纯信号。通过对经典测试信号和模拟水下探伤Mk4小型多回波测量仪测量的探伤噪声信号进行去噪,验证了该降噪方法的可行性。该方法具有CEEMDAN分解和渐进半软阈值综合性能的优点,与一般CEEMDAN和小波包去噪方法相比降噪效果更好,可应用于类似含噪探伤信号的降噪处理。

For the noise reduction of underwater injury-containing noise-containing signals, a new method of taking wavelet packet analysis based on CEEMDAN decomposition for comprehensive noise reduction is proposed. Firstly, wavelet packet denoising is used to pre-process the initial noisy information, and multiple characteristic modal components are obtained by means of CEEMDAN decomposition, and the modal components containing dominant noise are selected by autocorrelation function;then the modal components of dominant noise are denoised by using progressive semi-soft threshold, and then the final pure signal is obtained by signal reconstruction. The feasibility of the noise reduction method is verified by denoising the classical test signal and the probing noise signal measured by the simulated underwater probing Mk4small multi-echo measuring instrument. The method has the advantages of CEEMDAN decomposition and progressive semi-soft threshold synthesis, and the noise reduction effect is better compared with the general CEEMDAN and wavelet packet denoising methods, which can be applied to the noise reduction processing of similar noise-containing flaw signals.