汽车运用工程大作业

....汽车运用工程大作业....１汽车动力性计算（加速性能、最高车速、动力因素－加速时间和加速距离）已知：发动机外特性、装载质量、整备质量、总质量、车轮半径、传动系效率、滚动阻力系数、空气阻力系数×迎风面积、主减速器速比飞轮转动惯量、两个前轮转动惯量、四个后轮转动惯量、变速器速比、轴距、质心至前轴距离、质心高度。例如，已知数据如下表:项目单位数值装载质量kg1995整备质量kg1700总质量kg3695车轮半径m0.37传动系效率0.87滚动阻力系数0.012空气阻力系数×迎风面积m22.60主减速器速比5.83飞轮转动惯量kgm20.22两前轮转动惯量kgm21.80四后轮转动惯量kgm23.60轴距m3.40质心至前轴距离m2.0质心高度m0.9变速器速比变速器I档II档III档IV档V档四档6.123.111.691.00五档3.552.771.651.000.83....发动机外特性Tq=a+a1(n/c)+a2(n/c)2+a2(n/c)3+a3(n/c)4参数aa1a2a2a3c数值-19.31296-16540.9-3.8510001)绘制汽车驱动力与行驶阻力平衡图；2)求汽车的最高车速、最大爬坡度；3)绘制加速度倒数曲线4)用图解法或编程绘制汽车动力因数特性曲线5)图解手工绘制II档起步，加速至70km/h的车速－时间曲线以及距离－时间曲线。1、绘制汽车驱动利于行驶阻力平衡图m1=1995;m2=1700;mz=3695;g=9.81;f=0.0125-0.0025;nt=0.87+0.025;cda=2.60;r=0.37;n=600:1:4600;i0=5.83;ig1=6.12;ig2=3.11;ig3=1.69;ig4=1.00;ua1=0.377*r.*n/(ig1.*i0);ua2=0.377*r.*n/(ig2.*i0);ua3=0.377*r.*n/(ig3.*i0);ua4=0.377*r.*n/(ig4.*i0);a=-19.31;a1=296;a2=-165;a3=40.9;a4=-3.85;c=1000;tq=a+a1*(n/c)+a2*(n/c).^2+a3*(n/c).^3+a4*(n/c).^4;ft1=tq.*ig1.*i0.*nt/r;ft2=tq.*ig2.*i0.*nt/r;ft3=tq.*ig3.*i0.*nt/r;ft4=tq.*ig4.*i0.*nt/r;fz1=mz.*g.*f+cda*ua1.^2/21.15;%fz=Ff+Fwfz2=mz.*g.*f+cda*ua2.^2/21.15;fz3=mz.*g.*f+cda*ua3.^2/21.15;fz4=mz.*g.*f+cda*ua4.^2/21.15;plot(ua1,ft1,ua2,ft2,ua3,ft3,ua4,ft4,ua1,fz1,ua2,fz2,ua3,fz3,ua4,fz4);title('驱动力与行驶阻力平衡图');Xlabel('ua(km/h)');....Ylabel('ft(N)');gtext('Ft1')gtext('Ft2')gtext('Ft3')gtext('Ft4')gtext('Ff+Fw')2、求汽车的最高车速、最大爬坡度1）汽车的最高车速当Ft=Ff+Fw时,汽车处于稳定状态,并达到最高车速用matlab对驱动力与行驶阻力图进行放大处理可得交点坐标为（106.53，1757.68）因此，uamax=106.53km/h2）最大爬坡度一档时有最大爬坡度,用matlab对驱动力与行驶阻力图进行放大处理可得当ua=8.56km/h时，Ft1-(Ff+Fw)最大值。m1=1995;m2=1700;mz=3695;g=9.81;f=0.0125-0.0025;nt=0.87+0.025;cda=2.60;r=0.37;i0=5.83;ig1=6.12;ig2=3.11;ig3=1.69;ig4=1.00;ua1=8.56;n=ua1.*ig1.*i0/(0.377.*r);....a=-19.31;a1=296;a2=-165;a3=40.9;a4=-3.85;c=1000;tq=a+a1*(n/c)+a2*(n/c).^2+a3*(n/c).^3+a4*(n/c).^4;ft1=tq.*ig1.*i0.*nt/rfz1=mz.*g.*f+cda*ua1.^2/21.15%fz=Ff+Fw输出：ft1=15415Nfz1=371.4871Ni=tanα=tan[arcsin(ft1-fz1)/(mz.*g)]可知：α=24.02°.i=tanα=0.443、绘制加速度倒数曲线n=600:1:4000;r=0.37;nt=0.87+0.025;f=0.0125-0.0025;m=3695;g=9.81;G=m.*g;CDA=2.60;If=0.22;Iw1=1.80;Iw2=3.60;i0=5.83;ig1=6.12;ig2=3.11;ig3=1.69;ig4=1.00;ua1=0.377*r.*n/(ig1.*i0);ua2=0.377*r.*n/(ig2.*i0);ua3=0.377*r.*n/(ig3.*i0);ua4=0.377*r.*n/(ig4.*i0);a=-19.31;a1=296;a2=-165;a3=40.9;a4=-3.85;c=1000;tq=a+a1*(n/c)+a2*(n/c).^2+a3*(n/c).^3+a4*(n/c).^4;b1=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig1.^2.*i0.^2.*nt)/(m.*r.^2);b2=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig2.^2.*i0.^2.*nt)/(m.*r.^2);b3=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig3.^2.*i0.^2.*nt)/(m.*r.^2);b4=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig4.^2.*i0.^2.*nt)/(m.*r.^2);ft1=tq.*ig1.*i0.*nt/r;ft2=tq.*ig2.*i0.*nt/r;ft3=tq.*ig3.*i0.*nt/r;ft4=tq.*ig4.*i0.*nt/r;fw1=CDA.*(ua1.^2)/21.15;fw2=CDA.*(ua2.^2)/21.15;fw3=CDA.*(ua3.^2)/21.15;fw4=CDA.*(ua4.^2)/21.15;D1=(ft1-fw1)./G;D2=(ft2-fw2)./G;D3=(ft3-fw3)./G;D4=(ft4-fw4)./G;a1=g.*(D1-f)/b1;....a2=g.*(D2-f)/b2;a3=g.*(D3-f)/b3;a4=g.*(D4-f)/b4;plot(ua1,1./a1,ua2,1./a2,ua3,1./a3,ua4,1./a4);title('加速度倒数曲线图');Xlabel('ua(km/h)');Ylabel('1/a(m/s^2)');gtext('1/a1')gtext('1/a2')gtext('1/a3')gtext('1/a4')4、用图解法或编程绘制汽车动力因数特性曲线n=600:1:4000;r=0.37;nt=0.87+0.025;f=0.0125-0.0025;m=3695;g=9.81;G=m.*g;CDA=2.60;If=0.22;Iw1=1.80;Iw2=3.60;i0=5.83;ig1=6.12;ig2=3.11;ig3=1.69;ig4=1.00;ua1=0.377*r.*n/(ig1.*i0);ua2=0.377*r.*n/(ig2.*i0);ua3=0.377*r.*n/(ig3.*i0);ua4=0.377*r.*n/(ig4.*i0);a=-19.31;a1=296;a2=-165;a3=40.9;a4=-3.85;c=1000;tq=a+a1*(n/c)+a2*(n/c).^2+a3*(n/c).^3+a4*(n/c).^4;....b1=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig1.^2.*i0.^2.*nt)/(m.*r.^2);b2=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig2.^2.*i0.^2.*nt)/(m.*r.^2);b3=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig3.^2.*i0.^2.*nt)/(m.*r.^2);b4=1+(Iw1+Iw2)./(m.*r.^2)+(If.*ig4.^2.*i0.^2.*nt)/(m.*r.^2);ft1=tq.*ig1.*i0.*nt/r;ft2=tq.*ig2.*i0.*nt/r;ft3=tq.*ig3.*i0.*nt/r;ft4=tq.*ig4.*i0.*nt/r;fw1=CDA.*(ua1.^2)/21.15;fw2=CDA.*(ua2.^2)/21.15;fw3=CDA.*(ua3.^2)/21.15;fw4=CDA.*(ua4.^2)/21.15;D1=(ft1-fw1)./G;D2=(ft2-fw2)./G;D3=(ft3-fw3)./G;D4=(ft4-fw4)./G;plot(ua1,D1,ua2,D2,ua3,D3,ua4,D4)title('汽车动力特性图');Xlabel('ua(km/h)');Ylabel('D');gtext('Ⅰ')gtext('Ⅱ')gtext('Ⅲ')gtext('Ⅳ')....5、图解手工绘制Ⅱ档起步，加速至70km/h的车速—时间曲线以及距离--时间曲线m=3695;g=9.8;G=m*g;nmin=600;nmax=4500;ig=[6.123.111.691.00];i0=5.83;nt=0.87+0.025;f=0.012-0.0025;r=0.37;cda=2.60;If=0.22;Iw1=1.80;Iw2=3.60;u1=0.377*r*nmin./ig/i0;u2=0.377*r*nmax./ig/i0;deta=0*ig;fori=1:4deta(i)=1+(Iw1+Iw2)/(m*r^2)+(If*(ig(i))^2*i0^2*nt)/(m*r^2);endua=[6:0.01:99];N=length(ua);n=0;Tq=0;Ft=0;inv_a=0*ua;delta=0*ua;Ff=G*f;Fw=cda*ua.^2/21.15;fori=1:Nk=i;ifua(i)=u2(2)n=ua(i)*(ig(2)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)^2+40.874*(n/1000)^3-3.8445*(n/1000)^4;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;elseifua(i)=u2(3)n=ua(i)*(ig(3)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)^2+40.874*(n/1000)^3-3.8445*(n/1000)^4;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;elsen=ua(i)*(ig(4)*i0/r)/0.377;Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)^2+40.874*(n/1000)^3-3.8445*(n/1000)^4;Ft=Tq*ig(4)*i0*nt/r;inv_a(i)=(deta(4)*m)/(Ft-Ff-Fw(i));delta(i)=0.01*inv_a(i