基于DSP的多频率电阻抗成像系统

A Multi-frequency EIT System Based on DSP

设计了基于DSP的主从式数据采集系统。PC机作为主控机 ,进行可视控制、图像重建、实时显示等操作 ;DSP实现电极选通、数据采集并与PC机进行数据通讯。采用直接数字合成 (DDS)技术构建双路正弦波及同步方波发生器 ,实现幅值、频率、相位等连续调节 ;调制信号经同相与正交解调 ,获取实部与虚部信息。测试结果表明 ,该系统 (16电极 )数据采集速度高达 14 9帧 /秒 ,误差为 1% 。

A master slave data acquisition system based on DSP is designed The master PC is responsible for visual control,image reconstruction and on time display,while DSP carries out the tasks, such as electrode selection,data acquisition and data communication with the master Based on DDS technique,the signal generator can create the sinewave and the square wave signals,and its amplitude,frequency and phase can be continuously adjusted The measured signal is demodulated by an analog multiplier,and the information of real and imaginary component is obtained The test results show that the system data acquisition(16 electrodes)speed could be as high as 149 frames per second,the error is 1% and the repeatabilityis excellent