利用阶跃信号数字处理技术测量频率响应

Measuring the frequency response with digital processing technique of step-like waveforms

在频率响应实验研究中,经常会遇到阶跃响应信号,由于阶跃信号函数不存在付里叶交换。因此,有必要研究讨论如何利用阶跃信号的特性来求取频率响应特性的问题。本文从理论和实验两方面分别讨论两种利用阶跃信号求取频率响应的算法,一种算法是完全付里叶变换法,简写为CFFT;另一种算法是差分付里叶变换法,简写为DFFT。通过比较这两种算法的误差精度,表明两种算法精度均能满足工程实验要求,二者均可使用,但是从微机上的运算速度和存贮能力看,建议尽可能使用DFFT算法。

This paper presents two methods to resolve the frequency response with two step-like waveforms respectively.One is the complete-FFT (CFFT),the other Derive-FFT (DFFT).According to the error of the two methods,both they are able to meet the engineering requirements and may be used in practice.But by comparing the computing speed and their data storing capacity,the latter will be recommended.