电容层析成像图像重建算法研究及敏感场仿真分析

【作者】 刘传美；

【导师】 刘仁学；

【作者基本信息】 北方工业大学 ， 控制理论与控制工程， 2010， 硕士

【摘要】 电容层析成像技术是基于电容敏感的原理的过程层析成像技术。与其他的检测技术相比该技术具有非辐射、非侵入、结构简单、成本低、适用范围广、安全性能好等优点,就目前来说,已经成为层析成像技术发展的主要的研究方向之一,也是一种极具发展潜力的测量技术。本课题的研究工作主要分为两个部分：其中之一就是对图像重建算法的研究,另外就是对电容传感器敏感场的仿真。主要研究工作和结果如下所示：1.通过编写软件程序,实现了目前常见的几种算法的成像实验,例如：线性反投影算法、迭代算法、正则化优化修正算法等。将这几种成像算法得到的图像重建结果进行了对比,并分别对这几种算法在成像质量及速率等方面进行分析。2.通过对目前成像算法的研究发现图像成像的质量还有待于进一步的提高,并在此基础上提出了一种基于QR分解的电容层析成像图像重建算法。这种方法是首先把成像系统的正问题的数学模型进行规范化和Tikhonov正则化处理后,再把QR分解的思想代入到成像方程的求解中,最终可以得到图像重建的结果。3.使用ANSYS有限元仿真软件,利用其静电场的分析模块功能对ECT电容传感器的敏感场进行模拟仿真。通过仿真,得到了电容传感器模型的节点电位等值云分布图以及电场力矢量分布图,并对其仿真结果进行必要地分析。通过图像重建实验,将得到的几种图像重建算法的实验结果进行对比,利用本文提出的图像重建算法得到的重建结果在图像质量以及图像重建速率上都有不同程度的改善。对传感器进行仿真,可以得到传感器模型的电位分布和电场矢量结果图。仿真结果体现了传感器敏感场特性,即在激励电极附近灵敏度高,而中心区域离激励电极较远灵敏度就比较低。更多还原

【Abstract】 Electrical capacitance tomography is based on the principle of capacitance-sensitive process tomography technology, it has the advantages of no radiation, non-invasive, simple structure, low cost, broad scope and better security, as in the current main research directions development on process tomography, is a great development potential measurement.The research topic is divided into two parts:one of them is researching on the image reconstruction algorithms, the other is sensitive to the capacitance sensor field simulation. The research work and results are as follows:1. By writing software programs, in the several imaging algorithms are studied in this paper：linear back projection algorithm, iterative algorithm, regularization optimal correction algorithm etc., for example. This several imaging algorithms of image reconstruction results will be compared on the imaging quality and speed.2. By studying the imaging algorithm will be found that the picture quality to be improved, based on QR decomposition of a kind of imaging algorithm is proposed, This is the first issue of the imaging model is standardized and Tikhonov regularization treatment, QR decomposition of thinking then substituted into the equation of the imaging, Final results of image reconstruction can be3. Application of finite element simulation software ANSYS, we can use its electrostatic field analysis module to simulate the capacitance sensor sensitive, we can get potential distribution and electric intensity distribution of the simulation model, and we can analyses them.Through the image reconstruction experiment, experimental results show the algorithm has advantages as regards the quality of reconstruction image and the reconstruction rate.Through the sensor simulation, we can get potential distribution and electric intensity distribution of the simulation model, the simulation results reflect the characteristics of the sensor sensitivity field, high sensitivity in the incentive electrode nearby, center area far from incentive electrode sensitivity is lower.更多还原