激光超声信号去噪方法的研究

针对激光超声信号信噪比低的问题,分析了干扰噪声的特点,设计了基于数字平均和小波分析相结合的数据采集与处理系统。利用外部同步触发技术,间隔采集若干次激光超声信号,将各次采样信号相加平均,最后选择合适的小波基、分解层数和阈值方法,对数字平均后的信号进一步进行小波去噪处理。实验结果表明,该方法能够有效去除信号中的干扰噪声,提高信号的信噪比(SNR)。

Research on de-noising method for laser ultrasonic signal

Aiming at the low SNR of laser ultrasonic signal,data acquisition and processing system based on digital average and wavelet analysis are designed by analyzing the characteristics of interference noise.By using synchronized trigger technology,laser ultrasonic signal are collected at regular intervals,and then all the sampled signals are summed and averaged.Eventually,appropriate wavelet base,decomposition level and the threshold method are determined,and wavelet de-noising is further performed for the signals after digital averaging.The experimental results show that this method can efficiently remove noise,and improve the signal noise ratio of laser ultrasonic signal.