基于FFT的高精度相位测量系统设计  

Design of High Precision Phase Measurement System Based on FFT

作　　者：崔永俊[1] 宋雪莹 刘坤 张祥 CUI Yongjun;SONG Xueying;LIU Kun;ZHANG Xiang(Key Laboratory of Instrumentation Science and Dynamic Measurement,Ministry of Education,Key Laboratory of National Defense Science and Technology on Electronic Measurement,School of Instrument and Electronics,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室电子测试技术国防科技重点实验室仪器与电子学院

出　　处：《电子器件》2019年第5期1190-1194,共5页Chinese Journal of Electron Devices

基　　金：国家自然科学基金项目(61335008)

摘　　要：针对模拟相位测量电路中存在的精度不高、测量系统体积较大等问题,设计了基于FFT的高精度相位测量系统。该系统以FPGA为控制与运算核心,用16位模数转换芯片AD7606对2路同频信号进行数据采集,采集的数据送至FPGA后,采用快速傅立叶变换法(FFT)进行相位差计算,结果传输到上位机,采用3σ准则和均值滤波方法剔除粗大测量值后,显示出相位差。经测试,系统的相位测量精度能够达到±0.05°,分辨率达到0.001°,符合预期设计目标。与传统的模拟相位测量法相比,该相位测量系统实现了数字化,集成化,测量精度高,能够满足实际测试要求。In order to solve the problems of low precision and large volume in analog phase measurement circuit,a high-precision phase measurement system based on FFT is designed.The system takes FPGA as the core of control and calculation,uses 16-bit analog-to-digital conversion chip AD7606 to collect data of two channels of same frequency signals.After the collected data is sent to FPGA,uses FFT to calculate the phase difference.The result is transmitted to the upper computer,and shows the phase difference after removing coarse measured values by using 3σcriterion and mean filtering method.After testing,the phase measurement accuracy of the system can reach 0.05 and the resolution can reach 0.001,which meets the expected design goal.Compared with the traditional analog phase measurement method,the phase measurement system realizes digitization,integration and high measurement accuracy,and can meet the actual test requirements.

关 键 词：快速傅立叶变换 现场可编程门阵列 高精度 AD7606 相位差测量 

分 类 号：TN274[电子电信—物理电子学]