多聲源方位偵測與聲源數量估算

Abstract

本論文提出一套在聲速以及聲源個數皆未知的情況下藉由分散式的麥克風陣列擷取到的聲音訊號估算聲源個數以及聲源方向的演算法。並在演算法中提出了一套結合特徵結構分析(Eigenstructure)和廣義互相關性演算法(GCC，Generalized Cross-Correlation)的時間延遲估算演算法(ES-GCC)。ES-GCC利用聲場中的特徵向量估算麥克風之間的時間延遲關係，論文中將說明ES-GCC較一般GCC來的穩定。在計算完時間延遲關係後，本論文利用最小平方法(Least square)估算出聲源方位以及目前的聲速。而在多聲源的情形下，藉由判斷聲速估算的合理性可以排除不正確的聲源角度，再經由累積估算結果並且套用Adaptive K-means++演算法，即可估算出聲源個數以及聲源角度。本論文實驗皆於真實環境中執行，用以測試本論文所提演算法的效能。

This work proposes a multiple sound source direction estimation and sound source number estimation method by using distributed microphone array without the information of sound velocity. This work also proposes an eigenstructure-based generalized cross correlation method (ES-GCC) for estimating time delay between microphones. Upon obtaining the time delay information, the sound source direction and velocity can be estimated by least square method. In multiple sound source case, the time delay combination among microphones is arranged such that the estimated sound speed value falls within an acceptable range. By accumulating the estimation result of sound source direction and using adaptive K-means++ algorithm, we can estimate the sound source number and direction for each source. Experimental results are carried out in the real environment to evaluate the performance of the proposed algorithm.