基于小波包分析的时反聚焦算法改进

Improvement of time reversal focusing algorithm based on wavelet packet analysis

在桩基检测中,多径效应会造成散射程度相对较小的损伤信号淹没在多径信号中,损伤信号很难分辨,如果信号混有噪声,损伤信号会被淹没,使检测信号的信噪比降低,降低信号检测系统的质量。为解决以上问题,提出了基于小波包分析的时反聚焦改进算法,即对现场测量的信号小波去噪,然后对去噪后的信号进行小波包分析,实现信号在损伤点处的聚焦和噪声抑制。实验结果表明,算法具有更好的聚焦和抑噪效果。

In the detection of pile foundation,the interference of multipath effect leads to that the damage echo signal with small scattering degree will be flooded in the multipath signals,and it is hard to distinguish the damage signal.If the signal is mixed with noise,the damaged signal will be flooded,and the signal to noise ratio of the detection will decrease,degrading quality of the signal detection system.In order to solve the above problems,the improved timereversal focusing algorithm based on wavelet analysis is proposed in this paper.Namely,denoise the signal wavelet generated from the signal measured on the spot,and then analyze the wavelet packet for the denoised signal,so as to achieve focusing and noise suppression at the dammage point of the signal.Experimental results show that the algorithm has better focusing and noise suppression effects.