clc clear all close all %% % *各參數(shù)設(shè)置* %--聲源相關(guān)參數(shù) fmin=500; fmax=2000; %Hz: 信源為一頻率漸變的余弦信號，最低頻率fmin，最高頻率fmax S_last=0.1; %s ：聲源持續(xù)時間 %--采樣和信號處理相關(guān)參數(shù) fs=3e6; %采樣率 ts=1/fs; %采樣間隔 T=0.12; %s: 搜集數(shù)據(jù)T秒，計算一次位置 tMic=0:1/fs:T-1/fs; %接收數(shù)據(jù)時間 nMic=length(tMic); %接收數(shù)據(jù)長度 %--物理參數(shù)設(shè)置 v=34000; %cm/s: 音速 %--聲源和MIC位置 單位CM d=30; %麥克風間距 Lco_S = [10,10]; Loc_A = [50-d,0]; Loc_B = [50,0]; Loc_C = [50+d,0]; %% % *模擬聲源信號及各MIC接收到的信號* %--產(chǎn)生聲源 t = 0:ts:S_last; %假設(shè)聲波持續(xù)時間0.2秒 s = chirp(t,fmin,S_last,fmax,’linear’);%源信號, 頻率線性遞增的余弦信號 nsource=length(s); %--畫出聲源的波形 figure(); plot(s); xlabel(’時間/itus’); ylabel(’振幅’); title(’聲音信號’); %--計算信源傳到各MIC之間的延遲點數(shù) diff_SA = sqrt(sum((Lco_S-Loc_A).^2))/v/ts; diff_SB = sqrt(sum((Lco_S-Loc_B).^2))/v/ts; diff_SC = sqrt(sum((Lco_S-Loc_C).^2))/v/ts; %--計算信源與個MIC之間的距離 dis_SA = sqrt(sum((Lco_S-Loc_A).^2)); dis_SB = sqrt(sum((Lco_S-Loc_B).^2)); dis_SC = sqrt(sum((Lco_S-Loc_C).^2)); %--信源到MIC的時間延遲 dis_AC=dis_SA-dis_SC; dis_BC=dis_SB-dis_SC; Lag_SA = dis_SA/v; Lag_SB = dis_SB/v; Lag_SC = dis_SC/v; %--轉(zhuǎn)化成相差點數(shù) diff_AC =round((Lag_SA-Lag_SC)/ts); diff_BC =round((Lag_SB-Lag_SC)/ts); %--MIC接收到的數(shù)據(jù) sigMicA=zeros(1,nMic); sigMicB=zeros(1,nMic); sigMicC=zeros(1,nMic); sigMicA(1+diff_SA:nsource+diff_SA)=s; sigMicB(1+diff_SB:nsource+diff_SB)=s; sigMicC(1+diff_SC:nsource+diff_SC)=s; %--信號時域圖 figure();subplot(3,1,1); plot(sigMicA); subplot(3,1,2); plot(sigMicB); subplot(3,1,3); plot(sigMicC); %% % *用GCC（Generalized Cross-Correlation） Phase Transform 算法估計時延差* if(DelayDifferAC<5000) distDiffAC=(DelayDifferAC-1)/fs*v; else distDiffAC=(DelayDifferAC-nMic-1)/fs*v; end A=distDiffBC; B=distDiffAC; M=4*A^3-B^3+6*A*B^2-10*A^2*B+4*d^2*A-2*d^2*B; N=-8*A^2-2*B^2+8*A*B; r3=M/N; M1=4*A^3-B^3+4*A*B^2-6*A^2*B+2*d^2*B-4*d^2*A; N1=8*A^2+2*B^2-8*A*B; r2=M1/N1; cos=(r3^2+d^2-r2^2)/(2*d*r3); sin=sqrt(1-cos^2); a=(50-d)+r3*cos;