汽車?yán)碚撜n后作業(yè)答案MATLAB

1、汽車?yán)碚撟鳂I(yè)MATLAB過程u7汽車功率平衡圖60u/(km/h)Ua/(km/h)燃油積極性-加速時(shí)間曲線源程序：第一章m=3880;g=9.8;r=0.367;x=0.85;f=0.013;io=5.83;CdA=2.77;lf=0.218;Iw1=1.798;Iw2=3.598;Iw=lw1+lw2;%變速器傳動(dòng)比ig=6.093.091.711.00;L=3.2;a=1.947;hg=0.9;n=600:1:4000;T=-19.313+295.27*n/1000-165.44*(門/1000)人2+40.874*(11/1000)A3-3.8445*(n/IOOO).%;Ft1=T*

2、ig*io*x/r;%計(jì)算各檔對(duì)應(yīng)轉(zhuǎn)速下的驅(qū)動(dòng)力Ft2=T*ig(2)*io*x/r;Ft3=T*ig(3)*io*x/r;Ft4=T*ig(4)*io*x/r;u1=0.377*r*n/(io*ig(1)；u2=0.377*r*n/(io*ig(2);u3=0.377*r*n/(io*ig(3);u4=0.377*r*n/(io*ig(4);u=0:130/3400:130;F仁m*g*f+CdA*u”2/21.15;%計(jì)算各檔對(duì)應(yīng)轉(zhuǎn)速下的驅(qū)動(dòng)阻力F2=m*g*f+CdA*u2.A2/21.15;F3=m*g*f+CdA*u3.A2/21.15;F4=m*g*f+CdA*u4.A2/21.1

3、5;figure(1);plot(u1,Ft1,-r,u2,Ft2,-m1,u3,Ft3,1-k,u4,Ft4,-b,u1,F1Jr,u2,F2,-m,u3,F3,k1,u4,F4,-b,LineWidth,2)title(,汽車驅(qū)動(dòng)力與阻力平衡圖,)；xlabel(u_a/km.hA-1)ylabel(T/N)gtext(F_t1)gtext(F_t2)gtext(F_t3,)gtext(F_t4,)gtext(F_f+F_w)%由汽車驅(qū)動(dòng)力與阻力平衡圖知，他們無交點(diǎn)，U4在最大轉(zhuǎn)速時(shí)達(dá)到最大umax=u4(3401)Ft1max=max(Ft1);imax=(Ft1max-m*g*f)/(

4、m*g)disp假設(shè)是后輪驅(qū)動(dòng))C=imax/(a/L+hg*imax/L)%附著率delta1=1+(lw1+lw2)/(m*rA2)+lf*ig(1)*rA2*ioA2*x/(m*rA2);delta2=1+(lw1+lw2)/(m*rA2)+lf*ig(2)*rA2*ioA2*x/(m*rA2);delta3=1+(lw1+lw2)/(m*rA2)+lf*ig(3)*rA2*ioA2*x/(m*rA2);delta4=1+(lw1+lw2)/(m*rA2)+lf*ig(4)*rA2*ioA2*x/(m*rA2);a1=(Ft1-F1)/(delta1*m);%加速度a2=(Ft2-F2)

5、/(delta2*m);a3=(Ft3-F3)/(delta3*m);a4=(Ft4-F4)/(delta4*m);h1=1./a1;%加速度倒數(shù)h2=1./a2;h3=1./a3;h4=1./a4;figure(2);plot(u1,h1,u2,h2,u3,h3,u4,h4,LineWidth2)title(,加速度倒數(shù)-速度曲線圖xlabel(u)ylabel(1/a,)gtext(1/a1)gtext(1/a2)gtext(1/a3)gtext(1/a4)%由加速度倒數(shù)-速度曲線圖可知u1min=min(u1);u1max=max(u1);u2min=u1max;u2min=min(u2

6、);u2max=max(u2);u3min=u2max;u3max=max(u3);u4min=u3max;u4max=70;x1=;x2=;x3=;x4=;y=3401;fori=1:3401;ifu3(i)=u3min;x1=0；endendq1=max(x1);ua3=u3(q1:y);a3=h3(q1:y);fori=1:3401;ifu4(i)=u4min;x2=i;elseifu4(i)=u4max;x3=i;endendq2=max(x2);q3=max(x3);ua4=u4(q2:q3);a4=h4(q2:q3);s1=trapz(h2,u2);%二擋運(yùn)行時(shí)間s2=trapz(

7、ua3,a3);s3=trapz(ua4,a4);s=s1s2s3;disp(積分得)t=sum(s)*1000/3600%總時(shí)間第二章Pe1=Ft1.*u1./3600;%計(jì)算各檔對(duì)應(yīng)轉(zhuǎn)速下的功率Pe2=Ft2.*u2./3600;Pe3=Ft3.*u3./3600;Pe4=Ft4.*u4./3600;P1=F1.*u1./(3600*x);%計(jì)算各檔對(duì)應(yīng)的各個(gè)車速下的行駛功率P2=F2.*u2./(3600*x);P3=F3.*u3./(3600*x);P4=F4.*u4./(3600*x);figure(3);plot(u1,Pe1,k,u2,Pe2,-m,u3,Pe3,-k,u4,Pe

8、4,-bk,u2,P2,k,u3,P3,ku4,P4,k,linewidth,2);gtext(Pel)gtext(Pe2)gtext(Pe3)gtext(Pe4)xlabel(u/(km/h);ylabel(P/kW);汽車功率平衡圖,);n=8151207161420122603300634033804;Ua=;Ua=0.377*r*n./(io*ig(4)ft=m*g*f+77/21.15)*Ua.A2;算各轉(zhuǎn)速對(duì)應(yīng)的各個(gè)車速下的行駛阻力Pe(1)=ft(1).*Ua(1)./(3600*x);%計(jì)算各轉(zhuǎn)速對(duì)應(yīng)的各個(gè)車速下的行駛阻力功率Pe(2)=ft(2).*Ua(2)./(3600*

9、x);Pe(3)=ft(3).*Ua(3)./(3600*x);Pe(4)=ft(4).*Ua(4)./(3600*x);Pe(5)=ft(5).*Ua(5)./(3600*x);Pe(6)=ft(6).*Ua(6)./(3600*x);Pe(7)=ft(7).*Ua(7)./(3600*x);Pe(8)=ft(8).*Ua(8)./(3600*x)B0=1326.81354.71284.41122.91141.01051.21233.91129.7;B1=-416.46-303.98-189.75-121.59-98.893-73.714-84.478-45.291;B2=72.73936.

10、65714.5257.00354.47632.85932.97880.7113;B3=-5.8629-2.0533-0.51184-0.18517-0.091077-0.05138-0.047449-0.00075215;B4=0.177680.0430720.00681640.00185550.000689060.000350320.00028230-0.000038568;b1=(B0(D)+(B1*Pe)+(B2*Pe(1f2)+(B3*PeT)+(B4*Pe人4);b2=(B0(2)+(B1(2)*Pe(2)+(B2(2)*Pe(2)A2)+(B3(2)*Pe(2)A3)+(B4(2)

11、*Pe(2)A4);b3=(B0(3)+(B1(3)*Pe(3)+(B2(3)*Pe(3)A2)+(B3(3)*Pe(3)A3)+(B4(3)*Pe(3)A4);b4=(B0(4)+(B1(4)*Pe(4)+(B2(4)*Pe(4)A2)+(B3(4)*Pe(4)A3)+(B4(4)*Pe(4)A4);b5=(B0)+(B1*Pe)+(B2*PeA2)+(B3*PeA3)+(B4*PeA4);b6=(B0(6)+(B1(6)*Pe(6)+(B2(6)*Pe(6)A2)+(B3(6)*Pe(6)A3)+(B4(6)*Pe(6)A4);b7=(B0)+(B1*Pe)+(B2*PeA2)+(B3*P

12、eA3)+(B4*PeA4);b8=(B0(8)+(B1(8)*Pe(8)+(B2(8)*Pe(8)A2)+(B3(8)*Pe(8)A3)+(B4(8)*Pe(8)A4);P=0.7;Qs=0；Qs(1)=(Pe(1)*b1)/(1.02*Ua(1).*p*g);Qs(2)=(Pe(2)*b2)/(1.02*Ua(2).*p*g);Qs(3)=(Pe(3)*b3)/(1.02*Ua(3).*p*g);Qs(4)=(Pe(4)*b4)/(1.02*Ua(4).*p*g);Qs(5)=(Pe(5)*b5)/(1.02*Ua(5).*p*g);Qs(6)=(Pe(6)*b6)/(1.02*Ua(6)

13、.*p*g);Qs(7)=(Pe(7)*b7)/(1.02*Ua(7).*p*g);Qs(8)=(Pe(8)*b8)/(1.02*Ua(8).*p*g);M=polyfit(Ua,Qs,2);UA=0.377*r*600/(ig(4)*io):1:0.377*r*4000/(ig4)*io);%|J表示車速Q(mào)S=polyval(M,UA);%0表示油耗figure(4);plot(UA,QS,linewidth*,2);8tme最高檔等速百公里油耗曲線);xlabel(Ua/(km/h),);ylabel(Qs/L);第三章io=5.175.435.836.176.33;Va=0.377*r*

14、n(7)./(io.*ig(4);Ps=46.9366;dispC假設(shè)以最高檔，較高轉(zhuǎn)速(n取3401)，最經(jīng)濟(jì)負(fù)荷(即90%負(fù)荷大約46.9366KW)行駛時(shí)油耗)qs=0；qs(1)=(Ps*b7)/(1.02*Va(1).*p*g);qs(2)=(Ps*b7)/(1.02*Va(2).*p*g);qs(3)=(Ps*b7)/(1.02*Va(3).*p*g);qs(4)=(Ps*b7)/(1.02*Va(4).*p*g);qs(5)=(Ps*b7)/(1.02*Va(5).*p*g);st=17.581316.212114.512613.377512.9185;%加速時(shí)間：(這里以最高檔

15、四檔、速度由0加速到94.93Km/h的時(shí)間)因與題1.3第三問求法相同，這里不在累述，可直接有計(jì)算機(jī)求得:figure(5);plot(qs,st,lineWidth,2)11holdonplot(qs,st5);gtext(517)gtext(543)gtext(583)gtext(617)gtext(633)title。燃油積極性-加速時(shí)間曲線，);xlabelC燃油經(jīng)濟(jì)性(qs/L);ylabelC動(dòng)力性-原地起步加速時(shí)間(st/s),);第四章4-3載荷質(zhì)量m/kg質(zhì)心iWjhg/rn軸距L/m質(zhì)心至前軸距離a/m制動(dòng)力分配系數(shù)3空載40800.8453.9502.1000.38滿載

16、92901.1703.9502.9500.381)前軸利用附著系數(shù)為:Lz b zhg后軸利用附著系數(shù)為:L 1 zaZhg空載時(shí)：。hg3.95 0.38 1.85 0.4130.845所以?？蛰d時(shí)后輪總是先抱死。滿載時(shí):hgb =3.95 0.38=1.171 0.4282。時(shí)：前輪先抱死。時(shí)：后輪先抱死利用MATLAB作圖得到下圖:142)由MATLAB計(jì)算知當(dāng)護(hù)0.8時(shí)，（空載）制動(dòng)效率為0.6720所以其最大制動(dòng)減速度為%max0.8g0.67200.5376g人公式:2UaO25.923.bmax1s3.61 0.02 應(yīng)3.6303025.92=6.57m 0.56g計(jì)算可得：滿

17、載時(shí)制動(dòng)效率為0.87因此其最大動(dòng)減速度abmax 制動(dòng)距離0.8g 0.87 0.696g1 s 3.62UaO25.92abmax1 0.02 0023.63030225.92 0.696g =5-34m3）A.若制動(dòng)系前部管路損壞GduFxb2GzgdtGFz2-(azg)后軸利用附著系數(shù)-aZhg后軸制動(dòng)效率Err1rhg/Lza/L代入數(shù)據(jù)得：空載時(shí)：B=0.45滿載時(shí)：Er=0.60a）空載時(shí)其最大動(dòng)減速度abmax0.8g 0.450.36g2代入公式:2UaOaO_25.92Sbmax0.023.60.022303。225.920.36g=10.09mb）滿載時(shí)其最大動(dòng)減速度a

18、bmax0.8g0.60.48g代入公式:s3.62aO25.92abmax0.023.60.02303。225.920.48g=7.63mB若制動(dòng)系后部管路損壞IGduFxbiGzgdtGFz1-(bzhg)前釉利用附著系數(shù)fN-bZhg前軸制動(dòng)效率Etf1fhg/L乙b/L代入數(shù)據(jù)空載時(shí)：Ef=0.57滿載時(shí)：Et=0.33a）空載時(shí)其最大動(dòng)減速度abmax0.8g0.570.456g入公式：12u2UaO3.611225.92abmax1ccc0.02“3023.60022annpm25.920.456g1b）滿載時(shí)其最大動(dòng)減速度abmax代入公式：0.8g0.330.264g13.6UaO2u尬25.92abmax4-50.023.60.023030225.920.264g=13.67m1）同步附著系數(shù)。2.70.651.250.8h；0632）因0.7。所以前輪先抱死