Design And Research Of Underwater Wireless Energy And Information Synchronous Transmission System

With the application of underwater wireless sensor networks becoming more and more complex,the energy supply and data transmission of underwater equipment have been paid more and more attention.At present,the surface docking station usually uses metal cable for energy replenishment and data exchange for underwater equipment,which obviously affects the task progress and efficiency,and can not meet the actual needs.Wireless power transfer via magnetic resonance coupling(WPTMRC)and near field communication technology(NFC)can use the near-field magnetic field coupling principle to exchange energy and information between the transceiver structures,so combining the two becomes an optional solution to solve the simultaneous transmission of energy and information.Based on the theory of equivalent circuit and near-field electromagnetic field,this thesis studies the wireless energy transmission technology and near-field communication technology,and provides a good solution for the problems of low efficiency,low communication rate and high bit error rate of underwater energy transmission.Based on the magnetic coupling resonance wireless energy transmission system model in the process of underwater energy transmission,combined with the loss model and equivalent circuit principle,this thesis analyzes the influence of different system parameters on the transmission characteristics in the process of underwater energy transmission.An overall design scheme of underwater wireless information and power transfer(SWIPT)system is proposed.According to the characteristics of magnetic coupling wireless transmission,using the principle that the voltage of the secondary circuit of the coupled wireless charging system coil can be coupled to the primary circuit,and the primary circuit can transmit the signal to the secondary circuit,a staggered modulation circuit communication scheme is proposed,which reduces the energy transmission loss,improves the communication rate,and realizes full duplex wireless energy and information synchronous transmission.In order to explore the influence of underwater environment on wireless magnetic coupling energy transmission,a wireless magnetic coupling energy transmission system is designed and built.The transmission efficiency of the system is tested in the water and in the air respectively,and the underwater influence is obtained through the analysis of the results.The circuit designed in this thesis is simulated and analyzed by using the electrical parameters of underwater environment to verify the effectiveness of the system.On the basis of simulation and analysis,the signal and power synchronous transmission circuit designed in this thesis is built in kind,realizing the modulation and demodulation circuit,transmitting circuit,receiving circuit and rectifying circuit.The single-chip microcomputer is used to generate the control signal,and the signal transmitting module is used to transmit.The signal received at the receiving end is received and stored through the serial port receiving module.The signal rate is set by computer,the power transmission efficiency is measured and calculated,and the bit error rate is calculated by comparing the contents of transmitter and receiver.The relationship among modulation depth,bit error rate,energy transmission efficiency and transmission distance is analyzed.Through simulation and hardware circuit experiments,the conclusion is drawn: the increase of transmission distance will reduce the energy transmission efficiency and increase the bit error rate,and increasing the modulation depth will reduce the energy transmission efficiency and reduce the bit error rate.