摘要
在电磁检测中 ,检测信号在空间上与被测缺陷对应 ,以时间基为基础的模拟信号处理方法有时很难实现频段内的有效滤波 ,数字滤波方法则可以达到精确滤波的目的。为此 ,提出了一种零相位的、通带最平的数字滤波器构造方法和以FFT(快速傅里叶变换 )为基础的快速频域数字滤波算法 ,可有效处理电磁检测信号中低频波动和高频干扰。
The signals of electromagnetic testing are directly related to faults or flaws in space domain. It is difficult to filter those spatial signals in the time domain with analog signal processing. So a method of frequency digital filter has been proposed in which a symmetrical frequency structure for producing the linear phase response of the filter and a digital Butterworth filter for producing the maximum flat frequency pass band are used. The rapid digital filtering algorithm is based on FFT(fast Fourier transform). The long term noise caused by the swing of sensor and the short term noise caused by electromagnetic waves can be removed successfully by the method.
出处
《无损检测》
2003年第4期195-197,共3页
Nondestructive Testing
基金
863计划资助项目 ( 2 0 0 1AA42 3 2 3 0 )
关键词
电磁检验
数字滤波器
降噪
信号处理
Electromagnetic testing
Digital filter
Denoise
Signal processing
