基於多重訊號分類演算法之即時平面聲源定位系統

傳統聲源定位的方法，是藉由聲源到達麥克風陣列中每支麥克風的時間差(TDOA，Time Difference of Arrival)，來回推聲源的入射角度，這種方法雖然計算量並不大，但是在空間中的解析度卻會受到取樣頻率的影響。本論文引用了目前聲源定位的諸多方法中，解析度較高的MUSIC(Multiple Signal Classification)演算法，此演算法即使在多聲源的情況下，不但可以得知聲源的數目，更可同時找出個別的入射角度，再利用粒子定位法(Particle Localization Method)實現二維平面的聲源定位。但在實際操作後，發現此演算法的計算量非常龐大，以至於無法直接套用在real-time系統中。因此，我們也採用了幾種解決方案，解決計算量過大的問題。另外在非理想環境中，定位結果容易受到環境雜訊以及回聲的影響，造成定位不穩定。因此，本論文還引入了兩種線性預估的方法，粒子濾波器(Particle Filter)以及卡爾曼濾波器(Kalman Filter)，事先對聲源位置做預測，來改善定位結果。從實驗結果發現，卡爾曼濾波器的誤差收斂速度比粒子濾波器要快，且對於移動聲源的追蹤也較佳。

關鍵字

聲源定位；聲源追蹤；粒子定位法；卡爾曼濾波器；粒子濾波器

並列摘要

Traditional sound source localization algorithms employed the TDOA(Time Difference of Arrival) between microphones in a microphone array to estimate the angle of incidence. Even though the computations of these methods are not huge, the spatial resolution is affected by the sampling rate. In this thesis we use a high resolution algorithm called multiple signal classification (MUSIC). In the multiple-source case, this method not only can determine the number of sources, but also their angles of incidence. Then we use particle localization method (PLM) to realize two dimension sound source localization. In practice, we notice that the computation load of MUSIC algorithm is too heavy to realize in real time. So we adopt several methods to solve this problem. In practice, the performance of the system is also affected by reverberation, and the steadiness of this method is not ideal. Thus, to improve the performance we use Particle Filter and Kalman Filter to track the sound source. From the experiment results, we can notice that the Kalman filter converged faster than the particle filter. The bias of the Kalman filter when it converged is also smaller than the particle filter. The ability of the Kalman filter to track moving source is also better than the particle filter.

並列關鍵字

sound source localization ； source tracking ； particle localization method ； Kalman filter ； particle filter

參考文獻

[30] 梁翰銘, “利用粒子濾波器與麥克風陣列進行直角座標上多聲源之追蹤,” 國立清華大學, 2012.

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國際替代計量

基於多重訊號分類演算法之即時平面聲源定位系統

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