Research On The Characteristics And Applications Of The Conduction Current Field In Conductive Medium

Conduction current field can be widely used in the fields of underwater and underground communication, remote sensing, remote control, positioning and monitoring, and so on. In special occasions, it has incomparable advantages over other traditional communication mode.Therefore,it’s of important scientific value and practical significance to do research on propagation and application technology of conduction current field. Propagation characteristics of conduction current field and how trawl balance sensor and level instrument work have been studied in this paper. On the basis, the hardware circuit has been designed and achieved. Finally, the monitoring of underwater net shape changes and measurement of object offset angles and deflection directions can be achieved.The main contents and work of this paper are as follows:(1) In order to provide theoretical support for the design of communication systems,the propagation mathematical model of conduction current field in conductive medium is established, the propagation characteristics of the conduction current field is analyzed, and the impact of medium parameters and frequency on the communication distance of the communication system is studied.(2) The mathematical model of four-electrode transceiver system of the trawl balance sensor is established , then study the design principles of trawl balance sensor system and the influence of electrode size, electrode distance and other factors on system. On the basis of the analysed theory, a trawl balance sensor system has been designed.(3) The mathematical model of level instrument with four launch electrodes and eight launch electrodes is established, the effects of different emission electrodes of level instrument on deflection direction and deflection angle is analyzed. Evetually, the level instrument system has been designed.(4) Based on the above theory, the hardware circuit is designed and the desired function is realized. The core processor of the digital system are FPGA and DSP, FPGA is mainly used as designing program interface, such as the operation of AD and DA, and its also used to preprocess the received data and exchange data with DSP via EMIF interface. DSP mainly used to compute algorithm and process the data transferred by FPGA.(5) Measurement system is designed with a dedicated PC display software, the information of underwater net shape and object deflection calculated by terminal is uploaded to PC through serial port. PC display software designed by VC and Labview is very intuitive and convenient , which can graphically display the measurement information.