基于填充式ECT传感器的图像重建

Image reconstruction based on infill ECT sensor

为提高电容层析成像(ECT)系统对于非规则截面管道的成像质量,提出了一种基于填充式ECT传感器的图像重建方法.建立了完整的填充式ECT传感器模型,计算了考虑管壁和填充材料存在的灵敏度分布,针对重建区域标定了空场和满场.利用已知的填充区的介电常数以及对灵敏度矩阵的拆分处理,建立了降维的ECT正问题模型.利用Landweber迭代法求解了相应的逆问题.对所提方法进行了仿真数据验证和实测数据验证.重建结果表明:填充材料的介电常数与重建区的低介电常数一致时所提方法可显著改善重建质量.

In order to improve the imaging quality of electrical capacitance tomography(ECT)system for irregular cross-section pipeline,an image reconstruction method based on infill ECT sensor was proposed.A complete model of infill ECT sensor was established.The sensitivity distribution considering the existence of pipe wall and filling material was calculated.The empty and full fields were calibrated for the reconstructed area.By using the already known dielectric constant of the filled region and the splitting treatment of the sensitivity matrix,a reduced dimension ECT forward problem model was established.Through the Landweber iterative method,the corresponding inverse problem was solved.The as-proposed method was verified by the simulation and measured data.The reconstruction results show that the as-proposed method can significantly improve the reconstruction quality when the dielectric constant of the filling material is consistent with the low dielectric constant of the reconstructed area.