汽車?yán)碚撜n后習(xí)題Matlab程序-2

1.3確定一輕型貨車的動(dòng)力性能（貨車可裝用 4擋或5擋變速器，任選其中的一種進(jìn)行整車性能計(jì)算）：1） 繪制汽車驅(qū)動(dòng)力與行駛阻力平衡圖。2） 求汽車最高車速，最大爬坡度及克服該坡度時(shí)相應(yīng)的附著率。3）繪制汽車行駛加速度倒數(shù)曲線，用圖解積分法求汽車用 2檔起步加速行駛至70km/h的車速一時(shí)間曲線，或者用計(jì)算機(jī)求汽車用2檔起步加速行駛至70km/h的加速時(shí)間。輕型貨車的有關(guān)數(shù)據(jù)：汽油發(fā)動(dòng)機(jī)使用外特性的Tq-n曲線的擬合公式為Tq 19.313295.27（-^）165.44（-^）240.874（-^）33.8445（-^）41000100010001000式中，Tq為發(fā)動(dòng)機(jī)轉(zhuǎn)矩（N?m）;n為發(fā)動(dòng)機(jī)轉(zhuǎn)速（r/min）。發(fā)動(dòng)機(jī)的最低轉(zhuǎn)速nmin=600r/min,最高轉(zhuǎn)速nmax=4000r/min。裝載質(zhì)量2000kg整車整備質(zhì)量1800kg總質(zhì)量3880kg車輪半徑0.367m傳動(dòng)系機(jī)械效率n=0.85滾動(dòng)阻力系數(shù)f=0.013空氣阻力系數(shù)X迎風(fēng)面積CDA=2.77m2主減速器傳動(dòng)比i0=5.83飛輪轉(zhuǎn)動(dòng)慣量lf=0.218kg?nf一前輪轉(zhuǎn)動(dòng)慣量Iw1=1.798kg?nf四后輪轉(zhuǎn)動(dòng)慣量Iw2=3.598kg?nf變速器傳動(dòng)比ig（數(shù)據(jù)如下表）I檔U檔川檔w檔V檔四檔變速器6.093.091.711.00-五檔變速器5.562.7691.6441.000.793軸距 L=3.2m質(zhì)心至前軸距離（滿載） a=1.974m質(zhì)心高（滿載） hg=0.9m解：Matlab程序：求汽車驅(qū)動(dòng)力與行駛阻力平衡圖和汽車最高車速程序：n=[600:10:4000];Tq=-19.313+295.27*(n/1000)-165.44*(門/1000)八2+40.874*(門/1000)八3-3.8445*(n/1000).A4;m=3880;g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.562.7691.6441.000.793];nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;lf=0.218;lw1=1.798;lw2=3.598;Ft仁Tq*ig(1)*i0*nT/r;Ft2=Tq*ig(2)*i0*nT/r;Ft3=Tq*ig(3)*i0*nT/r;Ft4=Tq*ig(4)*i0*nT/r;Ft5=Tq*ig(5)*i0*nT/r;ua1=0.377*r*n/ig(1)/i0;ua2=0.377*r*n/ig(2)/i0;ua3=0.377*r*n/ig(3)/i0;ua4=0.377*r*n/ig(4)/i0;ua5=0.377*r*n/ig(5)/i0;ua=[0:5:120];Ff=G*f;Fw=CDA*ua.A2/21.15;Fz=Ff+Fw;plot(ua1,Ft1,ua2,Ft2,ua3,Ft3,ua4,Ft4,ua5,Ft5,ua,Fz);title('驅(qū)動(dòng)力-行駛阻力平衡圖');xlabel('ua(km/s)');ylabel('Ft(N)');gtext('Ft1'),gtext('Ft2'),gtext('Ft3'),gtext('Ft4'),gtext('Ft5'),gtext('Ff+Fw');zoomon;[x,y]=ginput(1);zoomoff;disp('汽車最高車速=');disp(x);disp('km/h');汽車最高車速=99.3006km/h求汽車最大爬坡度程序：n=[600:10:4000];Tq=-19.313+295.27*(n/1000)-165.44*(門/1000)八2+40.874*(門/1000)八3-3.8445*(n/1000).A4;m=3880;g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.562.7691.6441.000.793];nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;lf=0.218;lw1=1.798;lw2=3.598;Ft仁Tq*ig(1)*i0*nT/r;ua1=0.377*r*n/ig(1)/i0;Ff=G*f;Fw1=CDA*ua1.A2/21.15;Fz1=Ff+Fw1;Fi1=Ft1-Fz1;Zoomon;imax=100*tan(asin(max(Fi1/G)));disp('汽車最大爬坡度=');disp(imax);disp('%');汽車最大爬坡度=35.2197%求最大爬坡度相應(yīng)的附著率和求汽車行駛加速度倒數(shù)曲線程序：clearn=[600:10:4000];Tq=-19.313+295.27*(n/1000)-165.44*(門/1000)八2+40.874*(門/1000)八3-3.8445*(n/1000)八4;m=3880;g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.562.7691.6441.000.793];nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;If=0.218;Iw1=1.798;Iw2=3.598;Ft1=Tq*ig(1)*i0*nT/r;Ft2=Tq*ig(2)*i0*nT/r;Ft3=Tq*ig(3)*i0*nT/r;Ft4=Tq*ig(4)*i0*nT/r;Ft5=Tq*ig(5)*i0*nT/r;ua1=0.377*r*n/ig(1)/i0;ua2=0.377*r*n/ig(2)/i0;ua3=0.377*r*n/ig(3)/i0;ua4=0.377*r*n/ig(4)/i0;ua5=0.377*r*n/ig(5)/i0;Fw仁CDA*ua"2/21.15;Fw2=CDA*ua2.A2/21.15;Fw3=CDA*ua3.A2/21.15;Fw4=CDA*ua4.A2/21.15;Fw5=CDA*ua5.A2/21.15;Ff=G*f;deta1=1+(Iw1+Iw2)/(m*rA2)+(If*ig(1)A2*i0A2*nT)/(m*rA2);deta2=1+(Iw1+Iw2)/(m*rA2)+(If*ig(2)A2*i0A2*nT)/(m*rA2);deta3=1+(Iw1+Iw2)/(m*rA2)+(If*ig(3)A2*i0A2*nT)/(m*rA2);deta4=1+(Iw1+Iw2)/(m*rA2)+(If*ig(4)A2*i0A2*nT)/(m*rA2);deta5=1+(Iw1+Iw2)/(m*rA2)+(If*ig(5)A2*i0A2*nT)/(m*rA2);a1=(Ft1-Ff-Fw1)/(deta1*m);ad1=1./a1;a2=(Ft2-Ff-Fw2)/(deta2*m);ad2=1./a2;a3=(Ft3-Ff-Fw3)/(deta3*m);ad3=1./a3;a4=(Ft4-Ff-Fw4)/(deta4*m);ad4=1./a4;a5=(Ft5-Ff-Fw5)/(deta5*m);ad5=1./a5;plot(ua1,ad1,ua2,ad2,ua3,ad3,ua4,ad4,ua5,ad5);axis([099010]);title('汽車的加速度倒數(shù)曲線');xlabel('ua(km/h)');ylabel('1/a');

gtext('1/a1');gtext('1/a2');gtext('1/a3');gtext('1/a4');gtext('1/a5');a=max(a1);af=asin(max(Ft1-Ff-Fw1)/G);C=tan(af)/(a/L+hg*tan(af)/L);disp('假設(shè)后輪驅(qū)動(dòng)，最大爬坡度相應(yīng)的附著率 =');disp(C);假設(shè)后輪驅(qū)動(dòng)，最大爬坡度相應(yīng)的附著率 =0.4219>>clearnT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;lf=0.218;lw1=1.798;lw2=3.598;L=3.2;a=1.947;hg=0.9;m=3880;g=9.8;G=m*g;ig=[5.562.7691.6441.000.793];nmin=600;nmax=4000;u1=0.377*r*nmin./ig/i0;u2=0.377*r*nmax./ig/i0;deta=0*ig;fori=1:5deta(i)=1+(lw1+lw2)/(m*rA2)+(lf*(ig(i)F2*iOA2*nT)/(m*「A2);endua=[6:O.O1:99];N=length(ua);n=O;Tq=O;Ft=O;inv_a=O*ua;delta=O*ua;Ff=G*f;Fw=CDA*ua.A2/21.15;fori=1:Nk=i;ifua(i)<=u2(2)n=ua(i)*(ig(2)*iO/r)/O.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000F2+40.874*(n/1000F3-3.8445*(n/1000)A4;Ft=Tq*ig(2)*iO*nT/r;inv_a(i)=(deta(2)*m)/(Ft-Ff-Fw(i));delta(i)=0.01*inv_a(i)/3.6;elseifua(i)<=u2(3)n=ua(i)*(ig(3)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(3)*i0*nT/r;inv_a(i)=(deta(3)*m)/(Ft-Ff-Fw(i));delta(i)=0.01*inv_a(i)/3.6;elseifua(i)<=u2(4)n=ua(i)*(ig(4)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000F2+40.874*(n/1000F3-3.8445*(n/1000)A4;Ft=Tq*ig(4)*i0*nT/r;inv_a(i)=(deta(4)*m)/(Ft-Ff-Fw(i));delta(i)=0.01*inv_a(i)/3.6;elsen=ua(i)*(ig(5)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(5)*i0*nT/r;inv_a(i)=(deta(5)*m)/(Ft-Ff-Fw(i));delta(i)=0.01*inv_a(i)/3.6;enda=delta(1:k);t(i)=sum(a);endplot(t,ua);axis([0800100]);title('汽車2檔原地起步換擋加速時(shí)間曲線');xlabel('時(shí)間t(s)');ylabel('速度ua(km/h)');>>ginput

ans=25.8223 70.073725.7467 70.0737所以汽車2檔原地起步換擋加速行駛至70km/h的加速時(shí)間約為25.8s2至廿2至廿蘭眥展2.7已知貨車裝用汽油發(fā)動(dòng)機(jī)的負(fù)荷特性與萬有特性。負(fù)荷特性曲線的擬合公式為：bB0 B為：bB0 BlPeB2Pe2B3R3B4FV其中，b為燃油消耗率［g/（kW?h）］；Pe為發(fā)動(dòng)機(jī)凈功率（kW）；擬合式中的系數(shù)隨轉(zhuǎn)速n變化。怠速油耗Qid0.299mL/s（怠速轉(zhuǎn)速400r/min）。計(jì)算與繪制題1.3中貨車的1） 汽車功率平衡圖。2） 最高檔與次高檔的等速百公里油耗曲線?；蚶糜?jì)算機(jī)求貨車按JB3352-83規(guī)定的六工況循環(huán)行駛的百公里油耗。計(jì)算中確定燃油消耗值 b時(shí),若發(fā)動(dòng)機(jī)轉(zhuǎn)速與負(fù)荷特性中給定的轉(zhuǎn)速不相等，可由相鄰轉(zhuǎn)速的兩根曲線用插值法求得。解：Matlab程序：汽車功率平衡圖程序：clearn=[600:10:4000];Tq=-19.313+295.27*(n/1000)-165.44*(門/1000)八2+40.874*(門/1000)八3-3.8445*(門/1000)八4;m=3880;g=9.8;G=m*g;ig=[5.56 2.7691.644 1.000.793];nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;If=0.218;Iw1=1.798;Iw2=3.598;ua1=0.377*r*n/ig(1)/i0;ua2=0.377*r*n/ig(2)/i0;ua3=0.377*r*n/ig(3)/i0;ua4=0.377*r*n/ig(4)/i0;ua5=0.377*r*n/ig(5)/i0;Pe1=Tq.*ig(1)*i0.*ua1./(3600*r);Pe2=Tq.*ig(2)*i0.*ua2./(3600*r);Pe3=Tq.*ig(3)*i0.*ua3./(3600*r);Pe4=Tq.*ig(4)*i0.*ua4./(3600*r);Pe5=Tq.*ig(5)*i0.*ua5./(3600*r);ua=[0:0.35:119];Ff=G*f;Fw=CDA*ua.A2/21.15;Pf=Ff*ua/3600;Pw=Fw.*ua/3600;Pe0=(Pf+Pw)./nT;Pe=max(Pe1);plot(ua1,Pe1,ua2,Pe2,ua3,Pe3,ua4,Pe4,ua5,Pe5,ua,Pe0,ua,Pe);axis([01190100]);title('汽車功率平衡圖');xlabel('ua(km/h)');ylabel('Pe(kw)');gtext('1'),gtext('2'),gtext(3),gtext('4'),gtext('5'),gtext('(Pf+Pw)/et'),gtext('Pe');最高檔與次高檔的等速百公里油耗曲線程序:clearn=600:1:4000;m=3880;g=9.8;G=m*g;ig=[5.562.7691.6441.000.793];nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;If=0.218;Iw1=1.798;Iw2=3.598;n0=[8151207161420122603300634033804];B00=[1326.81354.71284.41122.91141.01051.21233.91129.7];B10=[-416.46-303.98-189.75-121.59-98.893-73.714-84.478-45.291];B20=[72.37936.65714.5247.00354.47632.85932.97880.71113];B30=[-5.8629-2.0553-0.51184-0.18517-0.091077-0.05138-0.047449-0.00075215];B40=[0.177680.0430720.00681640.00185550.000689060.000350320.00028230-0.000038568];B0=spline(n0,B00,n);B1=spline(n0,B10,n);B2=spline(n0,B20,n);B3=spline(n0,B30,n);B4=spline(n0,B40,n);Ff=G*f;ua4=0.377*r*n/ig(4)/i0;ua5=0.377*r*n/ig(5)/i0;Fz4=Ff+CDA*(ua4.A2)/21.15;Fz5=Ff+CDA*(ua5.A2)/21.15;Pe4=Fz4.*ua4./(nT*3.6*1000);Pe5=Fz5.*ua5./(nT*3.6*1000);fori=1:1:3401

b4(i)=B0(i)+B1(i)*Pe4(i)+B2(i)*Pe4(i)A2+B3(i)*Pe4(i)A3+B4(i)*Pe4(i).A4;b5(i)=B0(i)+B1(i)*Pe5(i)+B2(i)*Pe5(i).A2+B3(i)*Pe5(i).A3+B4(i)*Pe5(i).A4;endpg=7.0;Q4=Pe4.*b4./(1.02.*ua4.*pg);Q5=Pe5*b5./(1.02.*ua5.*pg);plot(ua4,Q4,ua5,Q5);axis([01001030]);title('最高檔與次高檔等速百公里油耗曲線’)；xlabel('ua(km/h)');ylabel('百公里油耗(L/100km)');gtext('4'),gtext('5');最高輕與次高楊等速百公里油耗曲線3C262624222018161412W□ 10 203D40 50 60 70 80 90 100□afkir/M3.1改變1.3題中輕型貨車的主減速器傳動(dòng)比， 做出io為5.17、5.43、5.83、6.17、6.33時(shí)的燃油經(jīng)濟(jì)性一加速時(shí)間曲線，討論不同io值對(duì)汽車性能的影響。解：Matlab程序：主程序：io=[5.17,5.43,5.83,6.17,6.33];%輸入主傳動(dòng)比的數(shù)據(jù)fori=1:1:5y(i)=jiasushijian(io(i)); %求加速時(shí)間endy;fori=1:1:5b(i)=youhao(iO(i));%求對(duì)應(yīng)i0的六工況百公里油耗endb;plot(b,y,'+r')holdonb1=linspace(b(1),b(5),1oo);y1=spline(b,y,b1);%三次樣條插值plot(b1,y1);%繪制燃油經(jīng)濟(jì)性-加速時(shí)間曲線title('燃油經(jīng)濟(jì)性一加速時(shí)間曲線');xlabel('百公里油耗(L/1OOkm)');ylabel('加速時(shí)間s');gtext('iO=5.17'),gtext('iO=5.43'),gtext('iO=5.83'),gtext('iO=6.17'),gtext('iO=6.33');

子程序：(1)functiony=jiasushijian(i0)%求加速時(shí)間的處理函數(shù)n1=linspace(0,5000);%先求各個(gè)檔位的驅(qū)動(dòng)力nmax=4000;nmin=600;r=0.367;yita=0.85;CDA=2.77;f=0.013;G=(3880)*9.8;ig=[6.09,3.09,1.71,1.00];%i0=5.83fori=1:1:4uamax(i)=chesu(nmax,r,ig(i),i0);小速度uamin(i)=chesu(nmin,r,ig(i),i0);ua(i,:)=linspace(uamin(i),uamax(i),100);n(i,:)=zhuansu(ua(i,:),r,ig(i),i0);Ttq(i,:)=zhuanju(n(i,:));Ft(i,:)=qudongli(Ttq(i,:),ig(i),i0,yita,r);F(i,:)=f*G+CDA*(ua(i,:)A2)/21.15;力的和%i為檔數(shù)%計(jì)算各個(gè)檔位的最大速度與最%%i為檔數(shù)%計(jì)算各個(gè)檔位的最大速度與最%計(jì)算各個(gè)檔位的轉(zhuǎn)速范圍%求出各檔位的轉(zhuǎn)矩范圍%求出驅(qū)動(dòng)力%求出滾動(dòng)阻力和空氣阻質(zhì)量換算系數(shù)a(i,:)=1./(delta(i,:).*3880./(Ft(i,:)-F(i,:)));%求出加速度F2(i,:)=Ft(i,:)-F(i,:);end%下面分各個(gè)檔位進(jìn)行積分，求出加速時(shí)間temp1(1,:)=ua(2,:)/3.6;temp1(2,:)=1./a(2,:);n1=1;forj1=1:1:100ifua(3,j1)>max(ua(2,:))&&ua(3,j1)<=70temp2(1,n1)=ua(3,j1)/3.6;temp2(2,n1)=1./a(3,j1);n1=n1+1;endendn2=1;forj1=1:1:100ifua(4,j1)>max(ua(3,:))&&ua(4,j1)<=70;temp3(1,n2)=ua(4,j1)/3.6;temp3(2,n2)=1./a(4,j1);n2=n2+1;endendy=temp1(1,1)*temp1(2,1)+qiuji(temp1(1,:),temp1(2,:))+qiuji(temp2(1,:),temp2(2,:))+qiuji(temp3(1,:),temp3(2,:));end(2)functionua=chesu(n,r,ig,i0);%由轉(zhuǎn)速計(jì)算車速ua=0.377*r.*n/(ig*i0);functionn=zhuansu(ua,r,ig,i0);%求轉(zhuǎn)速n=ig*i0.*ua./(0.377*r);end(4)(4)functiony=zhuanju(n); %求轉(zhuǎn)矩函數(shù)y=-19.313+295.27.*(n./1000)-165.44.*(門./1000)八2+40.874.*(門./1000)八3-3.8445*(n./1000)八4;functiony=qudongli(Ttq,ig,i0,yita,r); %求驅(qū)動(dòng)力函數(shù)y=(ig*i0*yita.*Ttq)/r;endfunctionp=qiuji(x0,y0) %求積分函數(shù)n0=size(x0);n=n0(2);x=linspace(x0(1),x0(n),200);y=spline(x0,y0,x); %插值%figure;plot(x,y);p=trapz(x,y);end⑺％求不同i0下的六工況油耗functionb=youhao(i0);globalfGCDAyitamrIfIw1Iw2pgB0B1B2B3B4n %聲明全局變量ig=[6.09,3.09,1.71,1.00];r=0.367;yita=0.85;CDA=2.77;f=0.013;%i0=5.83;G=(3880)*9.8;If=0.218;Iw1=1.798;Iw2=3.598;m=3880; %汽車的基本參數(shù)設(shè)定n0=[8151207161420122603300634033804];B00=[1326.81354.71284.41122.91141.01051.21233.91129.7];B10=[-416.46-303.98-189.75-121.59-98.893-73.714-84.478-45.291];B20=[72.37936.65714.5247.00354.47632.85932.97880.71113];B30=[-5.8629-2.0553-0.51184-0.18517-0.091077-0.05138-0.047449-0.00075215];B40=[0.177680.0430720.00681640.00185550.000689060.000350320.00028230-0.000038568];n=600:1:4000;B0=spline(n0,B00,n);B1=spline(n0,B10,n);B2=spline(n0,B20,n);%使用三次樣條插值，保證曲線的光滑連續(xù)B3=spline(n0,B30,n);B4=spline(n0,B40,n);ua4=0.377*r.*n./(i0*ig(4));%求出發(fā)動(dòng)機(jī)轉(zhuǎn)速范圍內(nèi)對(duì)應(yīng)的III、IV檔車速F4=f*G+CDA*(ua4.A2)/21.15;%求出滾動(dòng)阻力和空氣阻力的和P_fw4=F4.*ua4./(yita*3.6*1000); %求出阻力功率fori=1:1:3401%用擬合公式求出各個(gè)燃油消耗率b4(i)=B0(i)+B1(i)*P_fw4(i)+B2(i)*(P_fw4(i)F2+B3(i)*(P_fW4(i)F3+B4(i)*(P_fw4()A4;endpg=7.06;%汽油的重度取7.06N/Lua4_m=[25,40,50];%勻速階段的車速s_m=[50,250,250];%每段勻速走過的距離b4_m=spline(ua4,b4,ua4_m);%插值得出對(duì)應(yīng)速度的燃油消耗率F4_m=f*G+CDA*(ua4_m.A2)/21.15; %車速對(duì)應(yīng)的阻力P_fw4_m=F4_m.*ua4_m./(yita*3.6*1000); %發(fā)動(dòng)機(jī)功率Q4_m=P_fw4_m.*b4_m.*s_m./(102.*ua4_m.*pg);Q4_a1=jiasu(40,25,ig(4),0.25,ua4,i0);Q4_a2=jiasu(50,40,ig(4),0.2,ua4,i0);Qid=0.299;tid=19.3;s=1075;Q_i=Qid*tid; %求出減速階段的燃油消耗量Q4all=(sum(Q4_m)+Q4_a1+Q4_a2+Q_i)*100/s;%IV檔六工況百公里燃油消耗量b=Q4all;(8)加速階段處理函數(shù)functionq=jiasu(umax,umin,ig,a,ua0,i0);globalfGCDAyitamrIfIw1Iw2pgB0B1B2B3B4n;%i0;ua1=umin:1:umax; %把速度范圍以1km/h為間隔進(jìn)行劃分delta=1+(Iw1+Iw2)/(m*rA2)+(If*igA2*i0A2*yita)/(m*rA2);PO=(G*f.*uaO./36OO+CDA*uaO.A3/7614O+(delta*m.*uaO/36OO)*a)/yita;P=(G*f.*ua1/3600+CDA.*ua1.A3/76140+(delta*m.*ua1/3600)*a)/yita;dt=1/(3.6*a); %速度每增加1km/h所需要的時(shí)間fori=1:1:3401 %重新利用擬合公式求出b與ua的關(guān)系bO(i)=BO(i)+B1(i)*PO(i)+B2(i)*(PO(i))A2+B3(i)*(PO(i))A3+B4(i)*(PO(i))A4;endb1=interp1(uaO,bO,ua1); %插值出各個(gè)速度節(jié)點(diǎn)的燃油消耗率Qt=P.*b1./(367.1.*pg); %求出各個(gè)速度節(jié)點(diǎn)的燃油消耗率i1=size(Qt);i=i1(2);Qt1=Qt(2:i-1);q=(Qt(1)+Qt(i))*dt./2+sum(Qt1)*dt; %求該加速階段的燃油消耗量282827.827.622727827.827.6227278燃油經(jīng)濟(jì)性一加速時(shí)間曲袋26626：42622613.3 13.4 13.5 13.6 137 13.8 13.9 14 14.1 142 H.3百公里油jK（LJWOkm）4.3一中型貨車裝有前后制動(dòng)器分開的雙管路制動(dòng)系，其有關(guān)參數(shù)如下：載荷質(zhì)量（kg）質(zhì)心高h(yuǎn)g/m軸距L/m質(zhì)心至前軸距離a/m制動(dòng)力分配系數(shù)B空載40800.8453.9502.1000.38滿載92901.1703.9502.9500.381）計(jì)算并繪制利用附著系數(shù)曲線和制動(dòng)效率曲線2）求行駛車速Ua=30km/h，在 =0.80路面上車輪不抱死的制動(dòng)距離。計(jì)算時(shí)取制動(dòng)系反應(yīng)時(shí)間 2=0.02s，制動(dòng)減速度上升時(shí)間 ；=0.02s。3）求制動(dòng)系前部管路損壞時(shí)汽車的制動(dòng)距離 s,制動(dòng)系后部管路損壞時(shí)汽車的制動(dòng)距離s'。解：Matlab程序:⑴求利用附著系數(shù)曲線和制動(dòng)效率曲線程序:cleark=4080;hgk=0.845;Lk=3.950;ak=2.10;betak=0.38;bk=Lk-ak;%空載時(shí)的參數(shù)mm=9290;hgm=1.170;Lm=3.950;am=2.950;betam=0.38;bm=Lm-am;%滿載時(shí)的參數(shù)z=0:0.01:1.0;figure(1);fai=z;fai_fk=betak*z*Lk./(bk+z*hgk);%空載時(shí)前軸的?ffai_fm=betam*z*Lm./(bm+z*hgm);%滿載時(shí)前軸的?ffai_rk=(1-betak)*z*Lk./(ak-z*hgk);%空載時(shí)后軸的?rfai_rm=(1-betam)*z*Lm./(am-z*hgm);%滿載時(shí)后軸的?rplot(z,fai_fk,'b--',z,fai_fm,'r',z,fai_rk,'b--',z,fai_rm,'r',z,fai,'k');title('利用附著系數(shù)與制動(dòng)強(qiáng)度的關(guān)系曲線’)；xlabel('制動(dòng)強(qiáng)度(z/g)');ylabel('利用附著系數(shù)?');gtext('?r(空載)'),gtext('?r(滿載)'),gtext('?=z'),gtext('?f(空載)'),gtext('?f(滿載)');figure(2);Efk=z./fai_fk*100;%空載時(shí)前軸的制動(dòng)效率Efm=z./fai_fm*100;Erk=z./fai_rk*100;Erm=z./fai_rm*100;plot(fai_fk,Efk,'b',fai_fm,Efm,'r',fai_rk,Erk,'b',fai_rm,Erm,'r');axis([010100]);title('前后制動(dòng)效率曲線');xlabel('附著系數(shù)?');

ylabel（制動(dòng)效率%'）;gtext（'Ef）,gtext（'Er'）,gtext（'EC,gtext（‘滿載'）,gtext（'空載'）;on■oo利用附著系數(shù)與制動(dòng)強(qiáng)度的關(guān)系曲線0.1 02D3 0.4 06 06 07D.S0.9 1制動(dòng)強(qiáng)度（2/g）6on■oo利用附著系數(shù)與制動(dòng)強(qiáng)度的關(guān)系曲線0.1 02D3 0.4 06 06 07D.S0.9 1制動(dòng)強(qiáng)度（2/g）6D421S642Or1UO.O.O.前后制動(dòng)效率曲線0.1 02 0.3 04 05 0.S 07 08 0.9 1附看秦?cái)?shù)屮8060403020O(2)問和(3)問程序：clearmk=4080;hgk=0.845;Lk=3.950;ak=2.10;betak=0.38;bk=Lk-ak;%空載時(shí)的參數(shù)mm=9290;hgm=1.170;Lm=3.950;am=2.950;betam=0.38;bm=Lm-am;%滿載時(shí)的參數(shù)z=0:0.01:1;fai_fk=betak*z*Lk./(bk+z*hgk);%空載時(shí)前軸的?ffai_fm=betam*z*Lm./(bm+z*hgm);%滿載時(shí)前軸的?ffai_rk=(1-betak)*z*Lk./(ak-z*hgk);%空載時(shí)后軸的?rfai_rm=(1-betam)*z*Lm./(am-z*hgm);%滿載時(shí)后軸的?rEfk=z./fai_fk*100;%空載時(shí)前軸的制動(dòng)效率Efm=z./fai_fm*100;Erk=z./fai_rk*100;Erm=z./fai_rm*100;t1=0.02;t2=0.02;ua0=30;fai=0.80;g=9.8;ak1=Erk(81)*g*fai/100;am1=Erm(81)*g*fai/100;Sk1=(t1+t2/2)*ua0/3.6+ua0A2/(25.92*ak1);%制動(dòng)距離Sm仁(t1+t2/2)*ua0/3.6+ua0A2/(25.92*am1);disp('空載時(shí)，汽車制動(dòng)距離Sk1=');disp(Sk1);disp('滿載時(shí)，汽車制動(dòng)距離Sm1=');disp(Sm1);ak2=fai*g*ak/(Lk+fai*hgk);am2=fai*g*am/(Lm+fai*hgm);ak3=fai*g*bk/(Lk-fai*hgk);am3=fai*g*bm/(Lk-fai*hgm);Sk2=(t1+t2/2)*ua0/3.6+ua0A2/(25.92*ak2);%制動(dòng)距離Sm2=(t1+t2/2)*ua0/3.6+ua0A2/(25.92*am2);Sk3=(t1+t2/2)*ua0/3.6+ua0A2/(25.92*ak3);Sm3=(t1+t2/2)*ua0/3.6+ua0A2/(25.92*am3);disp('空載時(shí)，前制動(dòng)器損壞，汽車制動(dòng)距離 Sk2=');disp(Sk2);disp('滿載時(shí)，前制動(dòng)器損壞，汽車制動(dòng)距離 Sm2=');disp(Sm2);disp('空載時(shí)，后制動(dòng)器損壞，汽車制動(dòng)距離 Sk3=');disp(Sk3);disp('滿載時(shí)，后制動(dòng)器損壞，汽車制動(dòng)距離 Sm3=');disp(Sm3);空載時(shí)，汽車制動(dòng)距離Sk1=7.8668滿載時(shí)，汽車制動(dòng)距離Sm1=5.6354空載時(shí)，前制動(dòng)器損壞，汽車制動(dòng)距離Sk2=10.0061

滿載時(shí)，前制動(dòng)器損壞，汽車制動(dòng)距離Sm2=7.5854空載時(shí)，后制動(dòng)器損壞，汽車制動(dòng)距離Sk3=8.0879滿載時(shí)，后制動(dòng)器損壞，汽車制動(dòng)距離Sm3=13.59865.11二自由度轎車模型的有關(guān)參數(shù)如下:總質(zhì)量繞總質(zhì)量繞Oz軸轉(zhuǎn)動(dòng)慣量軸距質(zhì)心至前軸距離質(zhì)心至后軸距離前輪總側(cè)偏剛度后輪總側(cè)偏剛度轉(zhuǎn)向系總傳動(dòng)比試求：m=1818.2kgIz3885kgm2L=3.048ma=1.463mb=1.585mki=-62618N/radk2=-110185N/radi=201) 穩(wěn)定性因數(shù)K、特征車速Uch。2) 穩(wěn)態(tài)橫擺角速度增益曲線ua、車速u=22.35m/s2) 穩(wěn)態(tài)橫擺角速度增益曲線ua、車速u=22.35m/s時(shí)的轉(zhuǎn)向靈敏度r。sw3)靜態(tài)儲(chǔ)備系數(shù)S.M.，側(cè)向加速度為0.4g時(shí)的前、后輪側(cè)偏角絕對(duì)值之差與轉(zhuǎn)彎半徑的比值R/R°(R°=15m)。4）4）車速u=30.56m/s時(shí)，瞬態(tài)響應(yīng)的橫擺角速度波動(dòng)的固有（圓）頻率 0、阻尼比、反應(yīng)時(shí)間與峰值反應(yīng)時(shí)間解：Matlab程序：m=1818.2;Iz=3885;L=3.048;a=1.463;b=1.585;k1=-62618;k2=-110185;i=20;g=9.8;R0=15;u1=30.56;K=m*(a/k2-b/k1)/LA2;Uch=(1/K)〈/2);%特征車速disp(穩(wěn)定性因數(shù)(sA2/mA2)K=');disp(K);disp('特征車速(m/s)Uch=');disp(Uch);u=0:0.05:30;S=u./(L*(1+K*u.A2));%穩(wěn)態(tài)橫擺角速度增益plot(u,S);title('汽車穩(wěn)態(tài)橫擺角速度增益曲線');xlabel('車速u(m/s)');ylabel('穩(wěn)態(tài)橫擺角速度增益');disp('u=22.35m/s時(shí)，轉(zhuǎn)向靈敏度為');disp(S(448));SM=k2/(k1+k2)-a/L;ay=0.4*g;A=K*ay*L;B=L/R0;R=L/(B-A);C=R/RO;%轉(zhuǎn)彎半徑比disp('靜態(tài)儲(chǔ)備系數(shù)S.M.=');disp(SM);disp(側(cè)向加速度為0.4g時(shí)前、后輪側(cè)偏角絕對(duì)值之差(rad)a1-a2=');disp(A);disp('側(cè)向加速度為0.4g時(shí)轉(zhuǎn)彎半徑比值R/R0=');disp(C);W0=L/u1*(k1*k2/(m*lz)*(1+K*uM2)F(1/2);% 固有(圓)頻率D=(-m*(k1*aA2+k2*bA2)-Iz*(k1+k2))/(2*L*(m*Iz*k1*k2*(1+K*u1A2))A(1/2));% 阻尼比t=atan((1-DA2)A(1/2)/(-m*u1*a*W0/(L*k2)-D))/(W0*(1-DA2)A(1/2));%反應(yīng)時(shí)間E=atan((1-DA2)A(1/2)/D)/(W0*(1-DA2)A(1/2))+t;%峰值反應(yīng)時(shí)間disp('車速u=30.56m/s時(shí)的瞬態(tài)響應(yīng)參數(shù)分別為：’)；disp('橫擺角速度波動(dòng)的固有(圓)頻率(rad)為');disp(W0);disp('阻尼比為');disp(D);disp('反應(yīng)時(shí)間(s)為')；disp(t);disp('峰值反應(yīng)時(shí)間(s)為')；disp(E);穩(wěn)定性因數(shù)(sA2/mA2)K=0.0024特征車速(m/s)Uch=20.6053u=22.35m/s時(shí)，轉(zhuǎn)向靈敏度為3.3690靜態(tài)儲(chǔ)備系數(shù)S.M.=0.1576(rad)a1-a2=側(cè)向加速度為0.4g時(shí)前、后輪側(cè)偏角絕對(duì)值之差(rad)a1-a2=0.0281側(cè)向加速度為0.4g時(shí)轉(zhuǎn)彎半徑比值R/RO=1.1608車速u=30.56m/s時(shí)的瞬態(tài)響應(yīng)參數(shù)分別為：橫擺角速度波動(dòng)的固有（圓）頻率（rad）為5.5758阻尼比為0.5892反應(yīng)時(shí)間（s）為0.18112）2）改變“人體-座椅”系統(tǒng)參數(shù)：fs 1.5~6Hz,s 0.125~0.5。分析aw、Law峰值反應(yīng)時(shí)間（s）為0.3899汽車穩(wěn)態(tài)汽車穩(wěn)態(tài)橫擺角速度増益曲線3.532.521.510.600 5 10 15 20 26 30車j?6.5車身-車輪雙質(zhì)量系統(tǒng)參數(shù)： fo1.5Hz, 0.25, 9, 10?！叭梭w-座椅”系統(tǒng)參數(shù)：fs3Hz,s0.25。車速u20m/s，路面不平度系數(shù)Gqn° 2.56108m3，參考空間頻率n0=0.1m-1。計(jì)算時(shí)頻率步長(zhǎng) f0.2Hz，計(jì)算頻率點(diǎn)數(shù)N180。1）計(jì)算并畫出幅頻特性 乙/q、Z2/Z1、q/z2和均方根值譜JG召f、:Gz2f、Gaf譜圖。進(jìn)一步計(jì)算 q、 z「 z2、 a、aw、Law值值隨fs、s的變化。3)分別改變車身-車輪雙質(zhì)量系統(tǒng)參數(shù)： f00.25~3Hz,0.125~0.5，4.5~18, 5~20。繪制z、fd、Fd/G三個(gè)響應(yīng)量均方根值隨以上四個(gè)系統(tǒng)參數(shù)變化的曲線。解：Matlab程序(1)問yps=0.25;%阻尼比Zgama=9;%剛度比丫mu=10;%質(zhì)量比卩fs=3;ypss=0.25;g=9.8;a0=10A(-6);f0=1.5;ua=20;Gqn0=2.56*10(8);n0=0.1;detaf=0.2;N=180;f=detaf*[0:N];lamta=f/f0;lamtas=f/fs;Wf=0*f;deta=((1-lamta.A2).*(1+gama-1/mu*lamta.A2)-1).A2+4*ypsA2*lamta.A2.*(gama-(1/mu+1)*lamta.A2).A2;z1_q=gama*sqrt(((1-lamta.A2).A2+4*ypsA2*lamta.A2)./deta);z2_z仁sqrt((1+4*ypsA2*lamta.A2)./((1-lamta.A2).A2+4*ypsA2*lamta.A2));p_z2=sqrt((1+(2*ypss*lamtas).A2)./((1-lamtas.A2).A2+(2*ypss*lamtas).A2));z2_q=gama*sqrt((1+4*ypsA2*lamta.A2)./deta);p_q=p_z2.*z2_q;jfg_Gqddf=4*piA2*sqrt(Gqn0*n0A2*ua)*f;jfg_Gzdd1f=z1_q.*jfg_Gqddf;jfg_Gzdd2f=z2_q.*jfg_Gqddf;jfg_Gaf=p_q.*jfg_Gqddf;sigmaqdd=sqrt(trapz(f,jfg_Gqddf.A2));%路面不平度加速度均方根值

sigmazdd仁sqrt(trapz(f,jfg_Gzdd1f42));%車輪加速度均方根值sigmazdd2=sqrt(trapz(f,jfg_Gzdd2f42));%車身加速度均方根值sigmaa=sqrt(trapz(f,jfg_Gaf.A2));%人體加速度均方根值fori=1:(N+1)iff(i)<=2Wf(i)=0.5;elseiff(i)<=4Wf(i)=f(i)/4;elseiff(i)<=12.5Wf(i)=1;elseWf(i)=12.5/f(i);endendkk=Wf.A2.*jfg_Gaf.A2;aw=sqrt(trapz(f,kk));%加權(quán)加速度均方根值Law=20*log10(aw/a0);%加權(quán)振級(jí)disp('路面不平度加速度均方根值為');disp(sigmaqdd)');disp(sigmazdd1);');disp(sigmazdd2);');disp(sigmaa);');disp(aw);disp('車輪加速度均方根值為disp('車身加速度均方根值為disp('人體加速度均方根值為disp('加權(quán)加速度均方根值為disp('');disp(sigmazdd1);');disp(sigmazdd2);');disp(sigmaa);');disp(aw);figure(1)plot(f,z1_q),title('幅頻特性|z1/q|,(f=1.5Hz,Z=0.25,丫=9,卩=10)'),xlabel('激振頻率f/Hz'),ylabel('|z1/q|');figure(2)plot(f,z2_z1),title('幅頻特性|z2/z1|,(f=1.5Hz,Z=0.25,丫=9,卩=10)'),xlabel('激振頻率f/Hz'),ylabel('|z2/z1|');figure(3)plot(f,p_z2),title('幅頻特性|p/z2|,(fs=1.5Hz,Zs=0.25)'),xlabel('激振頻率f/Hz'),ylabel('|p/z2|');figure(4)plot(f,jfg_Gzdd1f),title('車輪加速度均方根值VGz1(f)譜圖'),xlabel('激振頻率f/Hz'),ylabel('VGz1(f)');figure(5)plot(f,jfg_Gzdd2f),title('車身加速度均方根值VGz2(f)譜圖'),xlabel('激振頻率f/Hz'),ylabel('VGz2(f)');figure(6)plot(f,jfg_Gaf),title('人體加速度均方根值VGa(f)譜圖'),xlabel('激振頻率f/Hz'),ylabel('VGa(f)');路面不平度加速度均方根值為0.3523車輪加速度均方根值為0.2391車身加速度均方根值為0.0168人體加速度均方根值為0.0161加權(quán)加速度均方根值為0.0100加權(quán)振級(jí)80.0291幅頻特ttlzVql,(1=15Hz.C=0.25,v=9,jj=1D)車輪加速度均方根值-VGzWit圖車身加速度均方根值曲龍①譜圖⑵問程序1:cleargama=9;%剛度比丫mu=10;%質(zhì)量比卩f0=1.5;g=9.8;a0=10A(-6);ua=20;Gqn0=2.56*10(8);n0=0.1;detaf=0.2;N=180;f=detaf*[0:N];lamta=f/f0;Wf=0*f;fori=1:(N+1)iff(i)<=2Wf(i)=0.5;elseiff(i)<=4Wf(i)=f(i)/4;elseiff(i)<=12.5Wf(i)=1;elseWf(i)=12.5/f(i);endendfs=3;ypss=0.25;ypss0=[0.125:0.005:0.5];a=0*ypss0;La=0*ypss0;M=length(ypss0);fori=1:Myps=ypss0(i);lamtas=f/fs;deta=((1-lamta.A2).*(1+gama-1/mu*lamta.A2)-1).A2+4*ypsA2*lamta.A2.*(gama-(1/mu+1)*lamta.A2).A2;p_z2=sqrt((1+(2*ypss*lamtas).A2)./((1-lamtas.A2).A2+(2*ypss*lamtas).A2));z2_q=gama*sqrt((1+4*ypsA2*lamta.A2)./deta);p_q=p_z2.*z2_q;jfg_Gqddf=4*piA2*sqrt(Gqn0*n0A2*ua)*f;jfg_Gaf=p_q.*jfg_Gqddf;kk=Wf.A2.*jfg_Gaf.A2;aw(i)=sqrt(trapz(f,kk));endLaw=20*log10(aw/a0);figure(1)plot(ypssO,aw);title('aw隨Zs的變化'),xlabel('“人體一座椅”系統(tǒng)的阻尼比Zs'),ylabel('aw/m*sA-2');figure(2)plot(ypssO,Law);title('Law隨Zs的變化'),xlabel('“人體一座椅”系統(tǒng)的阻尼比Zs'),ylabel('Law/dB');L躋隨爭(zhēng)的變化11人體一座椅啄疑的阻尼比g程序2:clearyps=0.25;%阻尼比Zgama=9;%剛度比丫mu=10;%質(zhì)量比卩f0=1.5;g=9.8;a0=10A(-6);ua=20;Gq門0=2.56*10八(-8);n0=0.1;detaf=0.2;N=180;f=detaf*[0:N];lamta=f/f0;Wf=0*f;fori=1:(N+1)iff(i)<=2Wf(i)=0.5;elseiff(i)<=4Wf(i)=f(i)/4;elseiff(i)<=12.5Wf(i)=1;elseWf(i)=12.5/f(i);endendypss=0.25;fs=[1.5:0.025:6];M=length(fs);fori=1:Mfs0=fs(i);lamtas=f/fs0;deta=((1-lamta.A2).*(1+gama-1/mu*lamta.A2)-1).A2+4*ypsA2*lamta.A2.*(gama-(1/mu+1)*lamta.A2).A2;p_z2=sqrt((1+(2*ypss*lamtas).A2)./((1-lamtas.A2).A2+(2*ypss*lamtas).A2));z2_q=gama*sqrt((1+4*ypsA2*lamta.A2)./deta);p_q=p_z2.*z2_q;jfg_Gqddf=4*piA2*sqrt(Gqn0*n0A2*ua)*f;jfg_Gaf=p_q.*jfg_Gqddf;kk=Wf.A2.*jfg_Gaf.A2;aw(i)=sqrt(trapz(f,kk));endLaw=20*log10(aw/a0);figure(3)plot(fs,aw);title('aw隨fs的變化'),xlabel('“人體一座椅”系統(tǒng)的固有頻率fs'),ylabel('aw/m*sA-2');

figure(4)plot(fs,Law);title('Law隨fs的變化'),xlabel('“人體一座椅系統(tǒng)的固有頻率fs'),ylabel('Law/dB');.5791Law隨丙的變化2 2.5 3 3.5 4 4.5 5 5.5?人1二一座椅誦統(tǒng)的固有頻率憶52.5791Law隨丙的變化2 2.5 3 3.5 4 4.5 5 5.5?人1二一座椅誦統(tǒng)的固有頻率憶528町.518185ao80579.3）問程序1：clearfigure(1)fs=3;yps_s=0.25;g=9.8;ua=20;Gqn0=2.56*10(8);n0=0.1;detaf=0.2;N=180;f0=1.5;yps=0.25;gama=9;mu=10;ff0=[0.25:0.05:3];sigmaz2=0*ff0;sigmafd=0*ff0;sigmaFd_G=0*ff0;M=length(ff0);fori=1:Mf0=ff0(i);f=detaf*[0:N];lamta=f/f0;lamtas=f/fs;deta=((1-lamta.A2).*(1+gama-1/mu*lamta.A2)-1).A2+4*ypsA2*lamta.A2.*(gama-(1/mu+1)*lamta.A2).A2;z2_qdot=2*pi*f*gama.*sqrt((1+4*ypsA2*lamta.A2)./deta);fd_qdot=gama*lamta.A2./(2*pi*f+eps)./sqrt(deta);Fd_Gqdot=2*pi*f*gama/g.*sqrt(((lamta.A2/(mu+1)-1).A2+4*ypsA2*lamta.A2)./deta);Gq_dotf=4*piA2*Gqn0*n0A2*ua;Gz2f=(z2_qdot).A2*Gq_dotf;Gfd_qf=(fd_qdot).A2*Gq_dotf;GFd_Gf=(Fd_Gqdot).A2*Gq_dotf;sigmaz2(i)=sqrt(trapz(f,Gz2f));sigmafd(i)=sqrt(trapz(f,Gfd_qf));sigmaFd_G(i)=sqrt(trapz(f,GFd_Gf));iff0==1.5

sgmz2=sigmaz2(i);sgmfd=sigmafd(i);sgmFd_G=sigmaFd_G(i);endendsz2=20*log10(sigmaz2/sgmz2);sfd=20*log10(sigmafd/sgmfd);sFd_G=20*log10(sigmaFd_G/sgmFd_G);plot(ff0,sz2,'r-',ff0,sfd,'b-.',ff0,sFd_G,'k--');axis([0.253-2515]);title('三個(gè)響應(yīng)量均方根值隨f0變化的曲線'),xlabel('車身部分固有頻率f0/Hz'),ylabel('cz2/dB,cfd/dB,cFd/G/dB');三個(gè)響應(yīng)量均方根僖隨1□變化的曲線151050-1015-20-250.5 1 15 2 2.5 0.5 1 15 2 2.5 3車身卻分固有clearfigure(2)fs=3;yps_s=0.25;g=9.8;ua=20;Gqn0=2.56*10(8);n0=0.1;detaf=0.2;N=180;f0=1.5;yps=0.25;gama=9;mu=10;c=(0.5-0.125)/180;yps0=[0.125:c:0.5];sigmaz2=0*yps0;sigmafd=0*yps0;sigmaFd_G=0*yps0;M=length(yps0);fori=1:Myps=yps0(i);f=detaf*[0:N];lamta=f/f0;lamtas=f/fs;deta=((1-lamta.A2).*(1+gama-1/mu*lamta.A2)-1).A2+4*ypsA2*lamta.A2.*(gama-(1/mu+1)*lamta.A2).A2;z2_qdot=2*pi*f*gama.*sqrt((1+4*ypsA2*lamta.A2)./deta);fd_qdot=gama*lamta.A2./(2*pi*f+eps)./sqrt(deta);Fd_Gqdot=2*pi*f*gama/g.*sqrt(((lamta.A2/(mu+1)-1).A2+4*ypsA2*lamta.A2)./deta);Gq_dotf=4*piA2*Gqn0*n0A2*ua;Gz2f=(z2_qdot).A2*Gq_dotf;Gfd_qf=(fd_qdot).A2*Gq_dotf;GFd_Gf=(Fd_Gqdot).A2*Gq_dotf;sigmaz2(i)=sqrt(trapz(f,Gz2f));sigmafd(i)=sqrt(trapz(f,Gfd_qf));sigmaFd_G(i)=sqrt(trapz(f,GFd_Gf));ifyps==0.25sgmz2=sigmaz2(i);sgmfd=sigmafd(i);

sgmFd_G=sigmaFd_G(i);endendsz2=20*log10(sigmaz2/sgmz2);sfd=20*log10(sigmafd/sgmfd);sFd_G=20*log10(sigmaFd_G/sgmFd_G);plot(yps0,sz2,'r-',yps