电容层析成像投影数据的采集系统设计

电容层析系统(ECT)可分为电容传感器阵列、投影数据采集系统和成像计算机三部分.通常的ECI系统中，每个电容极板都有自己的电容检测电路，对应于同一激励源的所有投影数据并行地转换成直流信号.研究了单片机控制的采用串行数据采集方案的ECT投影数据采集系统的设计.各极板共用一套电容检测电路，对应于同一激励源的所有投影数据串行地转换成直流信号，降低了硬件成本，消除了并行测量方式通道差异所带来的误差.论述了设计的整体方案、电容检测电路、极板控制电路、单片机单元电路和软件设计.给出了数据采集系统测试实验和ECT系统成像实验的结果.

Design of projection data acquisition system for electrical capacitance tomography

Electrical capacitance tomography(ECT) can be divided into three parts: capacitance sensor(sarray),projection data acquisition system and tomography computer.In usual ECT system,each electrode employs its own capacitance measuring circuit and the projection data derived from the same excitation(electrode) is converted into DC signals in parallel.A serial projectiondata-acquisition system controlled by a microcontroller was investigated.All the electrodes use a common capacitance measuring circuit,and the projection data derived from the same excitation electrode is converted into DC signals in serial,thus the hardware cost is reduced and the difference among the parallel measuring circuits is eliminated.The whole design scheme,electrode control circuit,single-chip-computer control circuit and software design were(illuminated.) Testing experiment results of the data-acquisition-system and the ECT image reconstruction were given