汽车理论课后习题matlab程序,汽车理论课后作业matlab编程详解(带注释).doc

汽车理论课后作业matlab编程详解(带注释)

1.3matlab程序：

(1)%驱动力-行驶阻力平衡图%货车相关参数。 m=3880;g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.56 2.769 1.644 1.00 0.793];y=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;n=600:10:4000; %发动机转数转换成汽车行驶速度。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; %计算各档位驱动力。Tq=-19.313+295.27*(n/1000)-165.44*(n/1000).^2+40.874*(n/1000).^3-3.8445*(n/1000).^4;Ft1=Tq*ig(1)*i0*y/r;Ft2=Tq*ig(2)*i0*y/r;Ft3=Tq*ig(3)*i0*y/r;Ft4=Tq*ig(4)*i0*y/r;Ft5=Tq*ig(5)*i0*y/r; %计算行驶阻力。Fz1=m*g*f+2.77*ua1.^2/21.15; Fz2=m*g*f+2.77*ua2.^2/21.15;Fz3=m*g*f+2.77*ua3.^2/21.15;Fz4=m*g*f+2.77*ua4.^2/21.15;Fz5=m*g*f+2.77*ua5.^2/21.15; %驱动力-行驶阻力平衡图。plot(ua1,Ft1,ua2,Ft2,ua3,Ft3,ua4,Ft4,ua5,Ft5,ua1,Fz1,'k',ua2,Fz2,'k',ua3,Fz3,'k',ua4,Fz4,'k',ua5,Fz5,'k');title('驱动力-行驶阻力平衡图'); xlabel('ua(km/s)');ylabel('Ft(N)');legend('Ft1','Ft2','Ft3','Ft4','Ft5','Ff+Fw') %求最高车速。[x,y]=ginput(1);disp(‘汽车最高车速=');disp(x);disp('km/h');

(2)%汽车最大爬坡度 clearclc%汽车相关参数。m=3880;g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.56 2.769 1.644 1.00 0.793];y=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;n=600:10:4000;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000).^2+40.874*(n/1000).^3-3.8445*(n/1000).^4;Ft1=Tq*ig(1)*i0*y/r; %一档时爬坡能力最强。ua1=0.377*r*n/ig(1)/i0;Ff=G*f; %滚动阻力。Fw1=CdA*ua1.^2/21.15; %空气阻力。Fz1=Ff+Fw1;Fi1=Ft1-Fz1;Fmax=max(Fi1/G);imax=100*tan(asin(Fmax));disp('汽车最大爬坡度=');disp(imax),disp('%');

(3)%求汽车加速度倒数曲线和最大爬坡度显得附着率。 clearclcm=3880; %汽车相关参数。g=9.8;nmin=600;nmax=4000;G=m*g;ig=[5.56 2.769 1.644 1.00 0.793];y=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; n=600:10:4000; %发动机转速范围。Tq=-19.313+295.27*(n/1000)-165.44*(n/1000).^2+40.874*(n/1000).^3-3.8445*(n/1000).^4; Ft1=Tq*ig(1)*i0*y/r; %各档位下的驱动力。Ft2=Tq*ig(2)*i0*y/r;Ft3=Tq*ig(3)*i0*y/r;Ft4=Tq*ig(4)*i0*y/r;Ft5=Tq*ig(5)*i0*y/r; ua1=0.377*r*n/