抗混叠滤波器对ECT系统性能的影响
2022,30(11):168-178
摘要：抗混叠滤波器已经广泛应用于电子仪器中。滤波器的截止频率和谐振系数是设计的两个主要参数，而另一个重要的参数，即动态响应的瞬态过程也需要考虑。然而，影响ECT系统数据采集速率的一个重要因素就是滤波器的时间延迟。因此，讨论了抗混叠滤波器的设计。通过理论分析、仿真和实验研究了LPF的阶跃响应，分别讨论了谐振因子、元件参数和LPF阶数对时延的影响，设计并测试了四阶抗混叠滤波器。实验结果表明：改进后的滤波器拥有更快的响应速度和较短的稳定时间。
关键词：抗混叠滤波器；ECT；时延；谐振因子；元件参数；滤波器阶数。
Influence of anti-aliasing filter on ECT system performance
Abstract：Anti-aliasing filters have been widely used in electronic instruments. The cut-off frequency and resonance coefficient of the filter are the two main parameters of the design, and the other important parameter, the transient process of the dynamic response, also needs to be considered. However, an important factor affecting the data acquisition rate of ECT system is the time delay of the filter. Therefore, the design of anti - aliasing filter is discussed. The step response of LPF is studied by theoretical analysis, simulation and experiment. The effects of resonance factor, element parameters and LPF order on the delay are discussed respectively. The fourth-order anti-aliasing filter is designed and tested. The experimental results show that the improved filter has faster response speed and shorter stability time.
Key words：Anti-aliasing anti-aliasing filter;Electrical Capacitance Tomography Technology;Time delay;Resonant factor;Component parameter;Filter order
收稿日期：2021-05-17
基金项目：国家自然科学基金资助项目（61871379），基于电阻抗成像的CFRP层压板结构健康检测方法研究。
