数字滤波器在位标器章动频率测试系统中的运用

Application of digital filter in tracker coordinator nutation frequency testing system

通过对位标器章动频率测试的混合信号进行频谱分析,针对频谱渐变的章动信号中的过强干扰信号的问题分别用陷波滤波法和窗函数法设计数字滤波器,比较2种滤波器信号处理后的通带纹波,阻带衰减与过渡频带等滤波器参数。本文首先对章动测试信号滤波器进行仿真,最后在工控机上实现。实验结果表明,FIR滤波器具有参数易于调整,稳定性好等优点,相对于IIR陷波滤波器避免了低频噪声滤除不全,影响最终测量结果精度的缺点,滤波性能更优,很好地实现了信号的实时滤波。

By analyzing the frequency spectrum of the nutation signals from tracker coordinator system, a notch filter and a band-pass FIR digital filter are designed, which is aimed at solving the problem of strong noise in spectrum continuous changing nutation signal. A compare of the filter result is made, including pass-band ripple, stop-band attenuation, transition bandwidth and other filter parameters. First, filter design and simulation methods using Matlab software are presented, and then implementation of filter is made on industrial controlling computer. The experimental result shows that FIR band-pass filter have the advantage of good stabilization, high resolution and convenience in parameter adjusting, and avoid the nonlinear phase and lower frequency noise problem in notch filter.