汽车理论图形MATLAB程序

功率平衡图

m=1230;g=9.8;

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);

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

end

end

figure

plot(ua,Ft,ua,Fz);

title('汽车驱动力与行驶阻力平衡图');

xlabel('ua(km/h)');

ylabel('Ft(N)');

text(20,6700,'Ft1');

text(40,4000,'Ft2');

text(50,2800,'Ft3');

text(80,2000,'Ft4');

text(100,1600, 'Ft5');

text(100,800,'Ff+Fw');

for k=1:56;

n=500:100:6000;

Pe(k)=Pemax*(n(k)/np+(n(k)/np)^2-(n(k)/np)^3);

Tq(k)=9549*Pe(k)/n(k);

Ft(k)=Tq(k)*ig(4)*i0*yt/r;

ua(k)=0.377*r*n(k)/(ig(4)*i0);

Fz(k)=m*g*f+CD*A*(ua(k)^2)/21.15;

E(k)=abs((Ft(k)-Fz(k)));

end

[Emin,kmin]=min(E);

Umax=ua(kmin)

加速度曲线图

m=1230;g=9.8;

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;

deta=[1.33 1.12 1.07 1.05 1.04];

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;

a(i,j)=(Ft(i,j)-Fz(i,j))/(deta(j)*m);

b(i,j)= 1./a(i,j);

end

end

x1=ua(:,1);y1=b(:,1);

x2=ua(:,2);y2=b(:,2);

x3=ua(:,3);y3=b(:,3);

x4=ua(:,4);y4=b(:,4);

x5=ua(:,5);y5=b(:,5);

figure

plot(x1,y1,x2,y2,x3,y3,x4,y4,x5,y5);

axis([0 185 0 15]);

title('汽车行驶加速度倒数曲线');

xlabel('ua(km/h)');

ylabel('1/a');

汽车二挡原地起步加速时间

nT=0.9;r=0.31;f=0.0177;CD=0.31;A=2.2;;i0=3.75;

m=3880;g=9.8;Pemax=83;np=6000;

G=m*g; ig=[3.615 2.053 1.393 1.031 0.837];

nmin=600;nmax=6000;

u1=0.377*r*nmin./ig/i0;

u2=0.377*r*nmax./ig/i0;

deta=[1.33 1.12 1.07 1.05 1.04];

ua=[1:0.01:180];N=length(ua);n=0;Tq=0;Ft=0;inv_a=0*ua;delta=0*ua; Ff=G*f;

Fw=CD*A*ua.^2/21.15;

for i=1:N

k=i;

if ua(i)<=u2(2)

n=ua(i)*(ig(2)*i0/r)/0.377;

Tq=9549*(Pemax*(n/np+(n/np)^2-(n/np)^3))/n;

Ft=Tq*ig(2)*i0*nT/r;

inv_a(i)=(deta(2)*m)/(Ft-Ff-Fw(i));

delta(i)=0.01*inv_a(i)/3.6;

elseif ua(i)<=u2(3)

n=ua(i)*(ig(3)*i0/r)/0.377;

Tq=9549*(Pemax*(n/np+(n/np)^2-(n/np)^3))/n;

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;

elseif ua(i)<=u2(4)

n=ua(i)*(ig(4)*i0/r)/0.377;

Tq=9549*(Pemax*(n/np+(n/np)^2-(n/np)^3))/n;

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;

else

n=ua(i)*(ig(5)*i0/r)/0.377;

Tq=9549*(Pemax*(n/np+(n/np)^2-(n/np)^3))/n;

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;

end

a=delta(1:k);

t(i)=sum(a);

end

plot(t,ua);

axis([0 80 0 100]);

title('汽车2档原地起步换挡加速时间曲线'); xlabel('时间t（s）');

ylabel('速度ua（km/h）');

功率平衡图

m=1230;g=9.8;

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;

deta=[1.33 1.12 1.07 1.05 1.04];

for j=1:5