Research On Inductively Coupled Power And Data Transmission Based Anchored Buoy

The development of marine resources is particularly important in the case of increasingly scarce land resources.The marine stereoscopic monitoring network is a modern marine monitoring device.And as an unmanned automatic ocean observatory,the marine buoy plays an irreplaceable role in the marine stereoscopic monitoring network.Ocean buoys provide all-weather,real-time,and reliable access to data from the marine environment.They can be used to measure hydro-meteorological elements such as currents,sea temperatures,tidal levels,wind speeds,and pressures.It is an important way for people to understand the ocean and obtain marine data.However,it is inconvenient to replace the battery since the ocean buoy is far away from the land,which brings disadvantages of high maintenance cost.Aiming at the problem that data can not be transmitted in real time in inductively coupled power and data time-sharing transmission for the ocean buoy,the power supply and data transmission methods of the existing marine buoy underwater systems at domestic and abroad from the actual situation of buoys are summarized and analyzed in this thesis.A contactless power and data transmission system was designed.The principle of inductive coupling was adopted in the system.The mooring cable was used as a transmission path connecting the above-water system and the underwater system.And the data bidirectional communication unit was designed.The power transmission and bidirectional data transmission of the system were realized by carrier coupling method through the two-stage coupler: the above-water coupler and the underwater coupler.Based on the principle of inductive coupling,the power transfer model of the system was established in this thesis.The static working characteristics and frequency splitting characteristics of the system were analyzed.Furthermore,the experimental system was built on the basis of theoretical analysis.The correctness of theoretical analysis was verified via the experimental results according to the results of system output power and efficiency under different coupling coefficients and different frequencies.And it is concluded that the transmission performance of the system is optimized by adjusting the operating frequency when the coupling coefficient is fixed.In this thesis,a pair of data coupling coils were added in the inductively coupled power transmission system to realize bidirectional transmission of data.The modulated data using on-off keying modulation was loaded onto the coupling coil.The carrier was transmitted to the underwater data receiver through inductive coupling.The induced voltage generated by the receiving coil was filtered and demodulated to realize data transmission.The circuit model of inductively coupled power and data transmission system was given.The influence of power transmission on data transmission was analyzed emphatically,and the data communication unit was designed.The power transmission experiment,data transmission experiment and complete performance test are carried out on the experimental system at the end of this thesis.The system output power reaches 25 W,the transmission efficiency reaches over 60%,and the reliability of data transmission is more than 95%.The underwater sensor has sufficient power to achieve a longer battery life,and the system works stably under long-term operation.The experimental results show that the system can meet the needs of experimental design and the working requirements of ocean buoys.