Research Of Source Localization Technology Based On Microphone Array With Time Delay Of Arrival Algorithm

In recent years,with deep research into microphone array,sound source localization technology based on microphone array is gradually applied in video conferencing,intelligent monitoring system,robot audio-visual system,impacting point measurement of military experiments,helicopter detection systems,industrial noise localization and other practical environments.These microphone array products facilitate our life and enhance our military strength.But now the sound source localization technology is restricted by the surrounding environment.Reverberation,environmental factors such as noise seriously affects the accuracy and real-time performance of the sound source localization algorithm.This thesis systematically studied the result of the reverberation signal in environment and how to improve the GCC algorithm to get the accuracy time delay.So we can improve the sound source localization technology accuracy and real-time performance.This thesis mainly has accomplished the following jobs:Firstly,the thesis studies the method of eliminating reverberation in a complex indoor environment and discusses the theory of eliminating reverberation based on complex cepstrum method and the design optimization of the filter parameter.By simulating and comparing in MATLAB,the thesis obtained the best filter parameters and doing reverberation simulation to voice signal which add gaussian noise under MATLAB.The classification and advantages and disadvantages of sound source localization algorithm is discussed.Aiming at the problem of cross-correlation peak function is not obvious,this thesis improves generalized cross-correlation algorithm by the parabola interpolation method and reducing the searching range method.Secondly,the sound source localization device based on DSP is designed including microphone pickup array,analog circuit processing part,DSP system and the peripheral circuit.The device can achieve four-way sound signal acquisition and the dominant frequency of DSP is 144M.This device can communication with RS232 serial port extended by DSP and the locating results can be real-time display.Thirdly,software based on DSP,peripheral circuitan and improved GCC time delay estimation algorithm is programmed.Quadratic parabola interpolated and peak value search range of the correlation function are both programmed in CCS software.Fourthly,a lot of localization experiments are tested in the laboratory environment to verify the feasibility of the algorithm.Results show that improving arithmetic can effectively increase position accuracy.Meanwhile,this thesis analyses the factor that may influence the results including microphone array position,angle and distance of sound source.