抗混叠滤波器对ECT系统性能的影响  

Influences on ECT System with Anti-aliasing Filter

作　　者：马敏 张曙旻 MA Min;ZHANG Shumin(School of Electronic Information and Automation,Civil Aviation University of China,Tianjin 300000,China)

机构地区：[1]中国民航大学电子信息与自动化学院,天津300000

出　　处：《计算机测量与控制》2022年第11期168-178,共11页Computer Measurement &Control

基　　金：国家自然科学基金项目(61871379)。

摘　　要：电容层析成像技术作为一种新型无损检测技术,因其具有无辐射、不会造成损伤、反应速度快等优点,广泛应用于油气输送、硫化床等工业领域,其数据采集速度和精度是评价性能的主要指标;影响电容层析成像系统数据采集速率的一个重要因素就是抗混叠滤波器的时间延迟;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,即动态响应的瞬时过程也需要考虑;因此,讨论了抗混叠滤波器的设计;通过理论分析、仿真和实验研究了滤波器的阶跃响应,分别讨论了谐振因子、元件参数和LPF阶数对时延的影响,设计了ECT数据采集平台测试了四阶抗混叠滤波器;实验结果表明:改进后的滤波器响应时间为25μs,与仿真结果基本一致;12电极电容层析成像系统图像采集速率可提升至1000帧/s,也取得了较好的成像结果。As a new nondestructive testing technology,electrical capacitance tomography(ECT)is widely used in oil and gas transportation,vulcanization bed and other industrial fields due to the advantages of no radiation,no damage and fast reaction speed.The data acquisition rate and accuracy are taken as the main indexes in ECT system,which are used to evaluate the performance.The time delay of anti-aliasing filter is an important factor affecting the data acquisition rate in the ECT system.The cut-off frequency,resonance coefficient and instantaneous process of dynamic response of the filter are the main parameters in the design,and the design of anti-aliasing filter is discussed.The step response of the filter is studied by the theoretical analysis,simulation and experiment.The effects of resonance factor,element parameters and LPF order on the time delay are discussed respectively.The ECT data acquisition platform is designed to test the fourth order anti-aliasing filter.The experimental results show that the response time of the improved filter is 25us,which is basically consistent with the simulation results,the image acquisition rate in the corresponding 12 ECT system is increased to 1000 FPS,which obtains the fine imaging quality.

关 键 词：抗混叠滤波器 电容层析成像 时间延迟 谐振因子 元件参数 滤波器阶数 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]