Research On Signal Detection And Processing Methods Of Bionic Sound Source Localization Mocrosensors

Sound source localization sensors play important roles in many fields such as military and civil.The principle,signal detection method,signal online processing method and signal offline processing method of the bionic sound source localization microsensor were studied in this paper.The main contents and conclusions are as follows:1.The principle of bionic sound source localization microsensor based on the auditory organs of the Ormia ochracea was studied.A bionic sound source localization coupled mechanical model was constructed based on the auditory organs of the Ormia ochracea,and the sensitivity of the bionic coupled mechanical model to small signal phase differences was analyzed through modal analysis.According to the electromechanical analogy theory,the bionic coupled mechanical model was equivalent to a bionic coupled circuit model.The phasor method was used to analyze the bionic coupled circuit model.Simulation analysis shows that the bionic coupled circuit model is sensitive to small phase differences of signals.2.The signal detection method of bionic sound source localization microsensor was studied.Based on the bionic coupling circuit model,a bionic sound source localization microsensor simulation system composed of an acquisition array,a detection circuit and a bionic coupling circuit model was constructed.The principle of the bionic sound source localization microsensor detection system was studied;based on the principle of the detection system,the detection system modules such as condenser silicon microphone,buffer module and preamplifier were studied;according to the research of the detection system,the schematic diagram and PCB of the detection circuit of the bionic sound source localization microsensor were designed in this paper;the effects of signal acquisition,amplification and filtering of the detection system are analyzed through simulation.3.The on-line processing method of bionic sound source localization signal based on phase sensitive detection was studied.Based on the phase sensitive detection method,a bionic sound source localization signal processing circuit was designed.According to the signal processing circuit scheme,this paper put forward an online signal processing algorithm which is easy to implement based on phase sensitive detection.Based on the signal characteristics of the bionic sound source localization microsensor,this paper put forward the pre-processing method and post-processing method of the bionic sound source localization signal,and constructed a complete bionic sound source localization signal processing scheme.The simulation results show that the on-line processing algorithm of the bionic sound source localization signal based on phase sensitive detection has a relative error within 2% when the SNR is greater than 10.4.The off-line processing method of bionic sound source localization signal based on improved generalized cross-correlation was studied.The time delay estimation method based on basic cross-correlation and generalized cross-correlation was studied and the antireverberation and anti-noise effects of generalized cross-correlation algorithm were analyzed by simulation.In order to enhance the anti-noise capability of generalized cross-correlation algorithm,the generalized cross-correlation algorithm was improved by introducing second cross-correlation,and a second generalized cross-correlation signal processing method was put forward in this paper.The simulation results show that the relative error of the generalized cross-correlation is within 2% when the SNR is greater than 1.7,and the relative error of the second generalized cross-correlation is within 2% when the SNR is greater than 1.1.Aiming at the error of generalized cross-correlation caused by limited sampling frequency,a crosscorrelation peak position correction method was put forward in this paper.Through interpolation,fitting and other approximate means,the continuous image of the peak of crosscorrelation function was restored to improve the accuracy of time delay estimation.The simulation results show that the cross-correlation peak position correction method can reduce the time delay estimation error by at least 5 ?s when the SNR is greater than 4.5.Experimental verification of the signal detection and processing methods of bionic sound source localization microsensors was carried out.A bionic sound source localization microsensor experiment platform was built.Based on the research of signal detection and processing methods,experimental system modules such as sound source module,detection system module,bionic coupling circuit module and output signal acquisition and processing module were built.Experimental verification and analysis were carried out under different sound wave incident angles,different sound source frequencies and noise-containing sound sources,the results show that the sound source localization error of the bionic sound source localization microsensor under different conditions is within 4°.The experimental results prove the feasibility and effectiveness of the signal detection and processing methods of bionic sound source localization microsensors.