工业总线标准电容层析成像系统设计

为保证电容层析成像(ECT)系统满足航空航天领域多相流参数测试的要求,开发了一套基于CPCI工业总线标准的ECT系统。采用高性能现场可编程门阵列(FPGA)芯片作为主控芯片,实现信号激励模块、多路复用开关模块、数据处理模块、数据解调和传输模块的集成式设计,将采集信号进行预处理,实现信号的滤波、放大和相敏解调,并通过CPCI工业总线接口把解调后的电容数据传送至系统上位机,完成图像重建。实验测试结果表明:系统采用1 MHz激励信号和8电极传感器的工作模式下,采用10周期的测试信号解调时,图像采集速度可达1 785幅/s,信号的信噪比高于60 d B,成像结果具有良好的空间分辨率。

Electrical capacitance tomography system design based on industrial bus standard

To ensure that the electrical capacitance tomography (ECT)system meets the requirements of multiphase flow parameter measurement in aerospace field,an ECT system based on the CPCI industrial bus standard is designed. A high-performance field-programmable gate array (FPGA)chip is used as the main control chip to realize the integrated design of signal excitation module,multiplex switch module,data process-ing module,data demodulation and transmission module. The signal is preprocessed with signal filtering,am-plification and phase-sensitive demodulation,and then the demodulated capacitance data is transferred to the host computer through the CPCI industrial bus interface. Finally,the image is reconstructed in the host com-puter. The experimental results of ECT system show that the image acquisition speed can reach 1785 frames per second at 1 MHz excitation signal with 8 electrode sensor and 10-cycle test signal for demodulation. The system can operate under a SNR of above 60 dB,while the imaging results have good spatial resolution.