同步迭代图像重建技术在电容层析成像系统中的应用

Simultaneous iterative reconstruction technique for electrical capacitance tomography

在电容层析成像 (ECT)系统中 ,为克服电容测量值数目有限以及管道内敏感场分布的“软场效应”,引入了一种同步迭代图像重建技术 (SIRT)。针对收敛速度和重建后图像的模糊效应 ,对 SIRT算法进行了改进。改进后的 SIRT算法使重建图像的速度和质量都有了明显的提高。对八电极ECT系统进行的仿真和静态实验结果表明 ,这种算法可望满足用于在线工业过程电容层析成像系统成像的要求。

A reconstruction algorithm named the simultaneous iterative reconstruction technique (SIRT) was introduced to resolve the main problems caused by the “soft field” effect and the limited number of measurements in electrical capacitance tomography (ECT). The process tomography speed and the smoothing effect of SIRT resulted in some improvements. Proper selection of the weight function and the filtering threshold based on maximum entropy theory significantly improved the speed and quality of reconstruction with the improved SIRT algorithm. Simulated and static experimental results show that this algorithm can be applied in an on line ECT system for industrial process.