Research On Sound Source Localization Based On Microphone Array

In the field of array signal processing,the sound source localization technology based on the microphone array is a research hotspot.The technology has been widely used in video conferencing,monitoring and surveillance systems,intelligent robots,and voice enhancement.In a real-life application scenario,due to interference from background noise and reverberation,the sound source signal quality received by the system is reduced.Therefore,how to perform effective sound source localization in a complex acoustic environment is still a challenging subject,and it has also attracted more and more attention from researchers.In this context,this paper is dedicated to the study of three-dimensional spatial sound source localization in the real environment,and has mainly done the following three aspects:（1）Aiming at the problem that the performance of time delay estimation algorithm based on sparse linear prediction is degraded under the environment with noise and reverberation,an improved sparse linear prediction model is proposed.In order to obtain the effective pre-filtering of the microphone signal,the sparseness of the speech amplitude spectrum and the sparsity of the linear prediction vector are simultaneously introduced into the least squares criterion to construct the convex constrained linear prediction model.Then the split-Bregman iterative method is used to solve the model.Finally,the signal of linear prediction error is used to establish a time delay estimator witch is based on the improved L₂/L₁-norm sparse linear prediction.The simulation results show that compared with the algorithms of GCC-PHAT and L₂/L₁-norm sparse linear prediction,the proposed algorithm has better performance of time delay estimation.（2）Considering the consistency with the actual sound source localization platform,in the localization algorithm based on delay estimation,a three-dimensional“folded zigzag”microphone array composed of 7 microphones was constructed.And the spherical interpolation algorithm is used to calculate the three-dimensional space coordinates of the target sound source.A simulation system for sound source localization is constructed,and the positioning effects of the three delay estimation algorithms are compared.（3）Aiming at the actual indoor environment,a three-dimensional spatial speech source localization system based on a 7-element microphone array was established.The system consists of two parts:a sound acquisition system and a sound source localization system.The sound acquisition system consists of a hardware structure composed of a microphone array and a synchronous data acquisition card,and a LabVIEW program for controlling it.The sound source localization system consists of signal preprocessing and endpoint detection procedures,delay estimation procedures,and positioning procedures.By performing sound source localization experiments on speaking sound sources located at different spatial locations,the applicability of the proposed improved L₂/L₁-LP time delay estimation algorithm in real scenarios is verified.