Ren Shangjie, Dong Feng
Tianjin Key Laboratory of Process Measurement and Control, School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China.
Tianjin Key Laboratory of Process Measurement and Control, School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
Philos Trans A Math Phys Eng Sci. 2016 Jun 28;374(2070). doi: 10.1098/rsta.2015.0333.
Electrical capacitance tomography (ECT) is a non-destructive detection technique for imaging the permittivity distributions inside an observed domain from the capacitances measurements on its boundary. Owing to its advantages of non-contact, non-radiation, high speed and low cost, ECT is promising in the measurements of many industrial or biological processes. However, in the practical industrial or biological systems, a deposit is normally seen in the inner wall of its pipe or vessel. As the actual region of interest (ROI) of ECT is surrounded by the deposit layer, the capacitance measurements become weakly sensitive to the permittivity perturbation occurring at the ROI. When there is a major permittivity difference between the deposit and the ROI, this kind of shielding effect is significant, and the permittivity reconstruction becomes challenging. To deal with the issue, an interface and permittivity simultaneous reconstruction approach is proposed. Both the permittivity at the ROI and the geometry of the deposit layer are recovered using the block coordinate descent method. The boundary and finite-elements coupling method is employed to improve the computational efficiency. The performance of the proposed method is evaluated with the simulation tests. This article is part of the themed issue 'Supersensing through industrial process tomography'.
电容层析成像（ECT）是一种非破坏性检测技术，用于根据在观测域边界上进行的电容测量来对其内部的介电常数分布进行成像。由于其具有非接触、无辐射、速度快和成本低等优点，ECT在许多工业或生物过程的测量中具有广阔前景。然而，在实际的工业或生物系统中，通常会在其管道或容器的内壁上看到沉积物。由于ECT的实际感兴趣区域（ROI）被沉积层包围，电容测量对在ROI处发生的介电常数扰动变得不那么敏感。当沉积物和ROI之间存在较大的介电常数差异时，这种屏蔽效应会很显著，并且介电常数重建变得具有挑战性。为了解决这个问题，提出了一种界面和介电常数同时重建方法。使用块坐标下降法恢复ROI处的介电常数和沉积层的几何形状。采用边界和有限元耦合方法来提高计算效率。通过模拟测试对所提出方法的性能进行评估。本文是主题为“通过工业过程层析成像实现超传感”的特刊的一部分。
