本文结合一个工业控制对象,提出了一种设计数字滤波器的工程方法。首先利用FFT方法对有用信号与噪声进行频率与幅值的定量分析,根据分析结果利用成熟的模拟网络理论设计相应模拟滤波器的传递函数,然后从模拟滤波器映射(变换)成数字滤波器。最后利用软件对所设计的数字滤波器进行检验。同时本文还给出了一个计算机辅助设计Butterwor-th低通数字滤波器的程序。 In this paper, an industrial control object, proposed a digital filter design engineering methods. First of all, we use FFT to quantitatively analyze the frequency and amplitude of the useful signal and noise. According to the analysis result, we use the mature analog network theory to design the transfer function of the corresponding analog filter and then map (transform) it into a digital filter from the analog filter. Finally, the design of the digital filter used to test. At the same time, this article also gives a computer-aided design Butterwor-th low-pass digital filter program.