汽车理论图形MATLAB程序

B5=polyfit(u5,b,3); for k=1:56

bh(k,1)=polyval(B1,ua(k,1)); bh(k,2)=polyval(B2,ua(k,2)); bh(k,3)=polyval(B3,ua(k,3));

bh(k,4)=polyval(B4,ua(k,4)); bh(k,5)=polyval(B5,ua(k,5)); end

for i=1:5

for k=1:56

Q(k,i)=Pz(k,i)*bh(k,i)/(1.02*ua(k,i)*7.10); end end

plot(ua(:,4),Q(:,4),ua(:,5),Q(:,5));

axis([0 185 0 20]);

title('最高档（五档）和次高档（四档）等速百公里油耗图'); xlabel('ua(km/h)'); ylabel('Qs(L/100km)'); text(90,10,'四档'); text(125,10,'五档');

爬坡度图

m=1230;g=9.8; G=m*g;

ig=[3.615 2.053 1.393 1.031 0.837]; i0=3.75; r=0.31;yt=0.9;f=0.017;CD=0.31;A=2.2; np=6000;Pemax=83; for i=1:56;

n=500:100:6000; Pe(i)=Pemax*(n(i)/np+(n(i)/np)^2-(n(i)/np)^3); Tq(i)=9549*Pe(i)/n(i); end

for j=1:5

for i=1:56

Ft(i,j)=Tq(i)*ig(j)*i0*yt/r; ua(i,j)=0.377*r*n(i)/(ig(j)*i0);

Fz(i,j)=m*g*f+CD*A*(ua(i,j)^2)/21.15; F=Ft-Fz;

I=tan(asin(Ft/G))*100; end end

plot(ua,I);

hold on; title('汽车的爬坡度图'); xlabel('ua(km/h)'); ylabel('i(%)'); text(50,55,'一档'); text(50,35,'二档'); text(100,22,'三档'); text(150,15,'四档'); text(200,13,'五档');

动力因数图 m=1230;g=9.8; G=m*g;

ig=[3.615 2.053 1.393 1.031 0.837]; i0=3.75; r=0.31;yt=0.9;f=0.017;CD=0.31;A=2.2; np=6000;Pemax=83;

%绘制汽车驱动力与行驶阻力平衡图 for i=1:56;

n=500:100:6000; Pe(i)=Pemax*(n(i)/np+(n(i)/np)^2-(n(i)/np)^3); Tq(i)=9549*Pe(i)/n(i); end

for j=1:5

for i=1:56

Ft(i,j)=Tq(i)*ig(j)*i0*yt/r; ua(i,j)=0.377*r*n(i)/(ig(j)*i0); Fw(i,j)=CD*A*(ua(i,j)^2)/21.15; F=Ft-Fw; D=F/G; end end

plot(ua,D); hold on;

axis([0 190 0 0.6]);

title('汽车的动力特性图'); xlabel('ua(km/h)'); ylabel('动力因数)'); text(40,0.5,'一档'); text(60,0.3,'二档'); text(100,0.2,'三档'); text(140,0.1,'四档'); text(140,0.04,'五档');