一种新型的三维ECT传感器及三维图像重建方法

Novel 3D ECT sensor and its 3D image reconstruction method

针对二维电容层析成像系统轴向分辨率低,对介电常数在轴向有显著变化介质的分布不适应,在分析电容层析成像基本原理的基础上,提出了一种新型的三维电容层析成像传感器结构。三维电容层析成像传感器检测电极分为3层布置在绝缘管道外壁,在测量时根据需求,采用双电极激励检测模式对同层或不同层之间极板阵列组合进行检测,以获得传感器内部介质的三维数据。实验结果表明,介质轴向分布图像更加客观和真实,与传统的单电极激励模式相比较,检测电容值得到提高,测量区灵敏度均衡性得到改善,图像重建精度得到提高。

Aiming at the low axial resolution of 2D electrical capacitance tomography and the inadaptability for the medium distribution with significant dielectric constant variation in the axial direction,a new 3D structure of the electrical capacitance tomography（ECT） sensor is presented.The detection electrodes of the 3D ECT sensor are arranged on the outside wall of an isolation tube in three layers.The 3D data of the sensor inside medium can be obtained by adopting dual electrode excitation detection mode for the array combinations of the electrode plates of the same layer or different layers as required in the measurement.Simulation experiment results show that compared with traditional single electrode excitation method,the image of the media is more objective and actual in axial distribution,the detected capacitance value is improved,the uniformity of the capacitance detection sensitivity is improved greatly,and the accuracy of the reconstructed image is also improved using the proposed method.