摘要
使用非线性时频分布对超声信号进行处理,充分考虑到了信号的时域、频域和相位的信息,根据超声信号在缺陷和噪声处瞬时频率的不同,结合超声信号的空间投影特点,提出了一种基于信号瞬时频率的超声信号处理方法.首先使用CWD把信号变换到时频域,估计出信号瞬时频率,然后通过瞬时频率的有序度对超声信号进行加权处理.该算法不仅消噪性能好,而且缺陷定位准确.
Considering the difference between the flaw signal and the noise signal, an ultrasonic signal process method is proposed based on instantaneous frequency and the ultrasonic signal＇s spatial distribution. First, the ultrasonic signal is put into the time-frequency domain by used of the Choi-Willianms distribution （CWD）. Then the signal instantaneous frequency is estimated by using the peak of the CWD. So, we can weightily process the ultrasonic signal depend on the degree of the instantaneous order. This method makes full use of the time domain, the frequency domain and the phase information of the ultrasonic signal. It can effectivelv stand out the signal of the flaw and restrain the noise.
出处
《武汉大学学报（工学版）》
CAS
CSCD
北大核心
2005年第5期128-130,150,共4页
Engineering Journal of Wuhan University
关键词
超声波检测
非线性信号处理
瞬时频率
ultrasonic testing
nonlinear signal processing
instantaneous frequency
