针对电容传感器测量区内的灵敏场受静电场"软场"的影响,存在灵敏度分布极不均匀的问题,在详细分析电容层析成像系统电容测量原理的基础上,提出一种三电极激励双电极检测方法,该方法采用三电极激励双电极检测方式使得相邻电极间有一个相对均匀的电场,同时增加独立测量检测数,改善求解的不适定性,提高测量区灵敏场的均衡性。利用ANSYS软件和Matlab软件对三电极激励双电极检测的电磁场特性进行系统仿真。仿真结果表明,与单电极激励方法相比较,采用三电极激励双电极检测方式,降低了信号检测电路的难度,测量区灵敏场的均衡性有了很大改善,提高了图像重建质量。
Aiming at the non-uniformity problem of sensitivity distribution caused by the "soft field" effect of the static electric field in the measurement region of capacitance sensor,on the basis of deeply analyzing the capacitance measuring principle in electrical capacitance tomography system,a triple-electrode-excitation and double-electrode-examine method is proposed.By using the new method,a more uniform electric field can be got,and the independent measurement data is also increased,which improves the ill-posed of the problems,enhances the uniformity of capacitance sensitivity.The electromagnetic properties of the sensor are simulated by utilizing the ANSYS and Matlab software.The experiment and calculation results show that the difficulty of measurement circuit is reduced.The uniformity of capacitance sensitivity is improved greatly with triple electrodes excitation and double electrodes examine method compared to singe electrode excitation method,and the quality of the reconstructed image is also improved.