Design Of Shallow Sea Terrain Detection System Based On Chaos

In recent years,with the further development of marine resources and the development of marine military equipment,shallow sea terrain detection has become the focus of attention of all countries in the world.However,due to the more complex multipath interference and reverberation in shallow seawater,the development of shallow sea exploration has been greatly limited.At present,the method of shallow-sea terrain detection mainly draws on the detection of deep-sea oceans and adopts an active sonar-type implementation scheme.The sonar's emission signal is dominated by single-frequency pulse signals or linear modulation signals.Therefore,there are widespread disadvantages such as large power,large volume,and low detection accuracy.In recent years,chaotic signals have been actively introduced into the underwater acoustics field because of their high randomness,strong autocorrelation and excellent noise immunity.Based on this topic,this paper designs a shallow sea terrain detection system using chaotic pulse signals as detection signals.In this paper,based on the study of sonar working methods and design process,the design requirements of the system are put forward based on practical application background.The system uses the chaotic signal as the system transmit signal,adopts the transceiving method to realize the energy conversion of the signal,and calculates the distance by calculating the time delay difference of the transmitted and received signals;In order to match the selected transducer,phase modulation is based on the chaotic sequence generated by the Logistic map.The power of the modulated signal is relatively concentrated and has a strong correlation.The accurate delay can still be obtained when the signal-to-noise ratio is not lower than-25 dB,and the anti-noise performance is good.After the form of the transmitted signal is determined,the overall scheme of the system is determined accordingly;Based on this,some transmitters,receivers,transceivers,and other circuits have been designed in conjunction with some parameters of the system.The circuit performance has been briefly analyzed.The entire circuit uses FPGA as the core to ensure the orderly execution of the system.In order to improve the processing speed of the data,the echo data is transmitted to the host computer via the USB for calculation.In addition,the host computer can make real-time changes to the system parameters to make the system become more flexible and easier to operate.After completing the system design,the various modules of the system were debugged.The results showed that the system can operate reliably.Based on this,the performance of the system is tested through specific experiments.The experiment shows that the detection accuracy of this system is within 10cm and the noise immunity is good,and it can meet the design requirements of the system.Compared with the traditional shallow sea detection system,the entire system has the characteristics of small size,low power,high detection accuracy,and good anti-noise performance,and is suitable for large area promotion and application.