Research On Sound Source Localization System Based On Microphone Array And Application

Sound source localization based on microphone array has become one of the hotspots in signal processing domains, which has wide application prospects in military, video conference, intelligent robot and speech enhancement. The related research works have strong value and theoretical significance.On the basis of research and analysis of three kinds of sound source localization method based on microphone array, the paper deeply researches the sound source localization algorithm based on time delay estimation; then elaborates the principle of time delay estimation algorithm, and verifies the accuracy of algorithm in the indoor environment; finally, a real-time sound source localization system is achieved and applied to the PTZ steering control, which obtains a more ideal application effect. The specific tasks are listed as follows:(1) Sound source localization:Three kinds of sound source localization methods based on microphone array are introduced:Ⅰ. The localization method based on high-resolution spectral estimation; Ⅱ. The localization method based on steered response optimum power; Ⅲ. The localization method based on time delay estimation (TDE), and presents the advantages and disadvantages of three method and applications.(2) Signal model and topology of microphone array:Firstly, Near-field, far-field signal model and an experience distinguishing formula are introduced in the paper. Secondly, four common topologies of microphone array which included linear array, T-type array, cross array and circular array are presented. Lastly, the paper studies how to choose a reasonable spacing of microphone array and the number of microphones.(3)Time delay estimation:In the method of sound source localization based on time delay estimation, the accuracy of sound source localization is determines by time delay estimation. The paper deeply studies the generalized cross correlation algorithm (GCC), adaptive delay estimation algorithm and sound source localization algorithm based on characteristics of the human ear; then discusses the performance of the GCC with different weighting function; finally, verifies the accuracy of time delay estimation algorithm in the indoor environment by experiments.(4) System implementation:The paper proposes a practicable system of sound source localization based on microphone array which is applied to PTZ steering control. First of all, the system calculates the position of sound source by sound source localization algorithm based on TDE, then controls camera to steer sound source by azimuth, which realizes real-time localization and automatic steering of dome. The experimental results show that the system has a higher accuracy to single sound source and high application value.