Design And Study Of A Communication Relay Buoy

The depletion of terrestrial energy is caused by the long-term development and utilization of terrestrial energy.With the passage of time,not only marine resources have become the focus of increasing attention,but also the protection of water environment has been paid more and more attention.Various intelligent unmanned submersibles and manned submersibles used for the development of marine resources and the detection of water environment have appeared one after another.But the unmanned submersible traditional mostly remote and autonomous,it is difficult to achieve the exchange of information and real-time two-way control node of the two water submersible,and the communication distance is limited;the manned submersible is mostly used way of communication cable and ship communication,this communication mode limits the flexibility of the manned submersible to a great extent and scope of work.The communication relay buoy as the communication relay between the surface control node and the underwater information node,mainly completes data transmission and instruction relay between them,and also expands the communication distance.It uses electromagnetic wave to propagate steadily in air medium and reduce attenuation of ultrasonic in water.The main technical routes are as follows:(1)The study focused on the wireless communication principle,this article analyzes its channel characteristics,and the theory is based on the principle of using nRF24L01 wireless transceiver chip design a wireless communication circuit,and then the experimental data transceiver on the actual circuit welding and debugging is completed,and the analysis of the data obtained.(2)The working principle and performance index of ultrasonic transducer are analyzed,and the equivalent circuit and matching impedance of ultrasonic transducer are obtained.According to the requirements of practical application,the technical index of the communication relay buoy is proposed,and the transducer is used for a horizontal non directional cylindrical ultrasonic transducer with a center frequency of 50 KHz.(3)Based on the center frequency of the ultrasonic transducer,the transmitter and receiver circuit in the underwater acoustic communication module are designed.The transmitter is mainly composed of IR2117 chip and IRFP460 power field effect transistor,and the receiving end is composed of NE5532 chip emitter follower with strong load capability,AD620 amplification circuit and four stage band-pass filter circuit.(4)STM32F103 is used as the main controller to produce ultrasonic wave.The period of the ultrasonic wave of 50 KHz is 20,and the controller can meet its frequency.Moreover,STM32F103 controller has rich peripheral interface and can do a lot of data operation and processing,which can meet the requirement of relay buoy as MIMO system.