Research On Bionic Autonomous Detection Technology For Underwater Nodes

With the proposal of Ocean Power Strategy and the deepening of smart ocean construction project,the use of UUV for unmanned underwater detection is the foundation and key to improving the transparency of underwater information in the future.Dolphins and other biological sonars can adapt to the harsh marine environment and have the advantages of autonomously adjusting the parameters of the transmitted signal and the detection logic.This paper makes full use of the advantages of biological sonar intelligence to deeply study the methods to improve the autonomous detection performance of underwater nodes from the perspective of bionics.Based on the establishment of a biological signal mathematical model,the adaptive parameter adjustment method of the bionic environment at the transmitting end and the bionic detection method at the receiving end of the underwater node are studied.In terms of adjusting the adaptive parameters of the bionic environment at the transmitting end,it takes full advantage of the good range resolution and speed resolution of biological signals in detection,and the advantages of better anti-reverberation capabilities.Based on the environment-aware channel estimation,the pulse overlap ratio adjustment method based on channel spectral filtering characteristics,the pulse interval adjustment method based on channel transmission delay characteristics,and the pulse sound source level adjustment method based on channel propagation loss characteristics are studied.Simulation studies show that the above three methods can effectively improve the continuous detection performance of unmanned platforms such as UUV and save launch energy consumption.For the channel estimation method based on environment perception,two algorithms,orthogonal matching pursuit(OMP)and L1 norm spectral projection gradient(SPGL1),are studied.The L1 norm spectral projection gradient algorithm with low prior requirement and high estimation accuracy is used to estimate the channel.In terms of bionic detection at the receiving end of underwater nodes.First,inspired by the frequency modulation characteristics of biological signals,a noise interference suppression algorithm based on fractional Fourier transform is studied.Simulation studies show that the algorithm can effectively filter out strong noise interference in the signal band;Secondly,inspired by biological binaural processing methods such as dolphins,a sidelobe suppression algorithm based on the nonlinear processing of biological left and right ears is studied.Simulation studies show that the algorithm can reduce sidelobe interference and improve the target's performance without significantly reducing the detection probability.Finally,inspired by the dolphin 's use of bubble nets to hunt bipolar pulse signals,a method for suppressing nonlinear scattering interference based on bipolar pulses was studied.Simulation studies show that this method can improve the detection probability of linear targets in strong scattering interference environments such as bubbles.