| 'Electronic Agriculture'is a new cross-discipline and is more and more focused by governments and relevant institutes. It is important that the advanced electronic measurement and process control technology are applied into agricultural production for the monitoring of plant tuber growing status, cultivation of new kinds of seeds, the fine cultivation of plant and so on.The ERT system used for monitoring the growth status of plant tuber in soil environment was designed in the dissertation. Effects of the electrode material and electrode array on ERT system, the demands of electrodes and exiciting sourace in soil were analyzed. It can provide the theoretical evidence for the further study of ERT system in soil environment.The simulation of sensitive field of ERT system in soil environment was complted using COMSOL software. The distributions of potential and electrical current density of electrical sensitive field in the condition of the opposite and adjacent exciting mode were analyzed. The influences of soil sensitive field caused by tuber position, size and number were studied according to the different soil characteristics.The AC impedance model in the soil environment was given and analyzed in the dissertation. Exciting frequency and soil resistance affect the electrodes and measuring results were analyzed.Thus, it could provide guidance for the electrodes design.The forward problem of ERT system was simulated employing the finite element analysis and COMSOL software.The node potential and boundary voltage were established and the solving process of forward problem in ERT system was given. Foundation of image reconstruction was built.The back projection method has been studied and the mathematical description was given. The algorithm was relized and optimized useing MATLAB and VC++. The results of image reconstruction were analyzed under the different conditions. |
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