电容耦合电阻层析成像并行电阻测量原理研究

传统的电阻层析成像(ERT)系统的电极与被测介质直接接触,容易产生电极极化、电化学腐蚀等问题,近年来出现的电容耦合非接触电导测量技术与ERT技术相结合的电容耦合电阻层析成像系统提出了一种新的非接触测量方法来解决此问题。但是目前该系统的电阻测量原理决定了其测量模式是串行的,成为限制系统数据采集速度的一个重要因素。针对该问题,本文引入了新的测量模型,提出了并行电阻测量原理,实现了数据采集系统,大大提高了系统速度。本文主要研究内容包括:分析了新型传感器的测量模型,提出了新的电阻求解方法;利用有限元法获得了新测量模型下管道内灵敏场分布;研制了相应的12电极样机系统。初步实验测试结果表明,该系统在具有较好测量精度的同时,其数据采集速度可达120帧/s,有效提高了电容耦合电阻层析成像系统的实时性。

Research on Parallel Resistance Measurement Principle for Capacitively Coupled Electrical Resistance Tomography

With the contact between the electrodes and liquid, the traditional electrical resistance tomography (ERT) system has some problems such as electrode polarization and electrode corrosion. Capacitively coupled electrical resistance tomography (CCERT) system, which combines ERT with capacitively coupled contactless conductivity detection technology, provides a non-contact measurement method to solve the problems. However, the measurement principle of the resistance of the CCERT system restricts the measurement mode to serial form, which is one of the main factors limiting data acquisition speed of the system. To solve this problem, this paper proposes a new measurement model and parallel resistance measurement principle, while parallel data acquisition system is developed. The main contributions are as follows: Firstly, the measurement model of the novel sensor is analyzed. The new resistance-calculation method is studied. Then based on this model, the sensitivity fields are obtained using finite element method. Finally, the 12-electrode prototyping system is designed. Test result shows that a data acquisition speed of more than 120 frames per second can be achieved, which means the proposed system improves the measurement speed of CCERT effectively.