汽車主減速器傳動(dòng)比優(yōu)化DOC

1、汽車主減速器傳動(dòng)比的優(yōu)化專業(yè)班級(jí)：車輛11級(jí)2班 姓名：韋永亮學(xué)號(hào)：2011 1097燃油經(jīng)濟(jì)性一加速時(shí)間曲線10.710.810.91111.111211.311.4百公里油耗(U100km)6 4 2 6 8 6 452 qate-K具2625.2526824262 52某輕型貨車，發(fā)動(dòng)機(jī)型號(hào)為 492QC-2，車有關(guān)數(shù)據(jù)如下。發(fā)動(dòng)機(jī)的最低轉(zhuǎn)速nmin = 600r/min ,最高轉(zhuǎn)速 nmax=4000r/min。整車質(zhì)量2000kg ;整車裝備質(zhì)量1800kg總質(zhì)量3880kg ;車輪半徑0.367m ;傳動(dòng)系機(jī)械效率nT = 0.85 ;滾動(dòng)阻力系數(shù)f = 0.013 ;空氣阻力系數(shù)

2、*迎風(fēng)面積CDA= 2.77m2 ;主減速器傳動(dòng)比i0 = 5.83 ;飛輪轉(zhuǎn)動(dòng)慣量If = 0.218kg.m2;二前輪轉(zhuǎn)動(dòng)慣量Iw1 = 1.798kg.m2 后四輪轉(zhuǎn)動(dòng)慣量Iw2 = 3.598kg.m21檔2檔3檔4檔5檔變速器傳動(dòng)比5.562.7691.6441.000.793汽油發(fā)動(dòng)機(jī)使用外特性的 Tq-n曲線的擬合公式為：Tq=-19.313+295.27*( n/1000)-165.44*(門/1000)人2+40.874*(門/1000)人3-3. 8445*( n/1000)A4.負(fù)荷特性曲線擬合公式為：b=B0+B1*Pe+B2*Pe.A2+B3*Pe.A3+B4*Pe.

3、A4.擬合公式中的系數(shù)為:N/(r/mi n)B0B1B2B3B48151326.8-416.4672.379-5.86290.1776812071354.7-303.9836.657-2.05530.04307216141284.4-189.751452.4-0.511840.006816420121122.9-121.597.0035-0.185170.001855526031141.0-98.8934.4763-0.0910770.0006890630061051.2-73.7142.8593-0.051380.0003503234031233.9-84.4782.9788-0.0474

4、490.0002823038041129.7-45.2910.71113-0.00075215-0.000038568怠速油耗Qid = 0.299mL/s(怠速轉(zhuǎn)速400r/min )。一.建模1. 優(yōu)化變量我們主要考慮，在汽車變速器傳動(dòng)比不變的情況下，汽車主減速器傳動(dòng)比對(duì)經(jīng)濟(jì)性和動(dòng)力性的影響。所以以主減速器傳動(dòng)比i0作為優(yōu)化變量。X=i02. 目標(biāo)函數(shù)針對(duì)該貨車，主要考慮優(yōu)化經(jīng)濟(jì)性，這樣的話要求在必要的動(dòng)力性條件下，要求最小的燃油消耗，即要求百公里油耗盡可能少。q=mi nf(X)3. 約束條件(1 )取咼車速要求maxUa(X)=100km/h(2)動(dòng)力性要求t(x)=32.5%(4)最

5、高檔動(dòng)力因數(shù)校核D0=D0=0.03二計(jì)算求解1. 計(jì)算加速時(shí)間nT=0.85; r=0.367; f=0.013; CDA=2.77; lf=0.218;Iw1=1.798; Iw2=3.598; L=3.2; a=1.947; hg=0.9; m=3880;g=9.8; G=m*g; ig=5.56,2.769,1.644,1.00,0.793;nmin=600; nmax=4000;i0=5.43;u=0.377*r* nm ax./ig/i0;for i=1:5deta(i)=1+(Iw1+Iw2)/(m*rA2)+(If*(ig(i)A2*i0A2* nT)/(mW2);質(zhì)量換算系數(shù)

6、endua=6:0.01:100;%最低穩(wěn)定車速6公里每小時(shí)N=le ngth(ua);n=0;Tq=0;Ft=0;i nv_a=0;delta=0*ua;%數(shù)據(jù)初始化Ff=G*f;Fw=CDA*ua.A2/21.15;for i=1:Nk=i;if ua(i)=u(2)%以二檔起步計(jì)算n=ua(i)*(ig(2)*i0/r)/0.377;Tq=-19.313+295.27*( n/1000)-165.44*(門/1000)人2+40.874*( n/1000)A3-3.8445*( n/1000)A4;Ft=Tq*ig (2) *i0* nT/r;in v_a(i)=(deta (2)*m)

7、/(Ft-Ff-Fw(i);%加速度倒數(shù)delta(i)=0.01* in v_a(i)/3.6;%加速時(shí)間elseif ua(i)=u(3)n=ua(i)*(ig(3)*i0/r)/0.377;Tq=-19.313+295.27*( n/1000)-165.44*(門/1000)人2+40.874*(門/1000)人3-3.8445*( n/1000)M;Ft=Tq*ig (3) *i0* nT/r;in v_a(i)=(deta(3)*m)/(Ft-Ff-Fw(i);delta(i)=0.01* in v_a(i)/3.6;elseif ua(i)=u(4)n=ua(i)*(ig(4)*i

8、0/r)/0.377;Tq=-19.313+295.27*( n/1000)-165.44*(門/1000)人2+40.874*(門/1000)人3-3.8445*( n/1000)M;Ft=Tq*ig (4) *i0* nT/r;in v_a(i)=(deta (4) *m)/(Ft-Ff-Fw(i);delta(i)=0.01* in v_a(i)/3.6;elsen=ua(i)*(ig(5)*i0/r)/0.377;Tq=-19.313+295.27*( n/1000)-165.44*(門/1000)人2+40.874*(門/1000)人3-3.8445*( n/1000)M;Ft=Tq

9、*ig (5) *i0* nT/r;in v_a(i)=(deta(5)*m)/(Ft-Ff-Fw(i);delta(i)=0.01* in v_a(i)/3.6;enda=delta(1:k); %定義矩陣t(i)=sum(a); %求和endplot(t,ua);axis(O 80 0 100);title(汽車二檔原地起步換擋加速時(shí)間曲線);xlabel(時(shí)間 t ( s);ylabel(速度 ua ( km/h);x,y=gi nput(1);disp(x);考慮到該貨車的最高車速很難達(dá)到100km/h(i0 為5.83時(shí)不到100km/h)以加速到70公里的時(shí)間作為加速時(shí)間。 a a

10、a io o汽車二檔原地起步換攔加速時(shí)間曲線100 Irt11r1一oo70改變i0的值得到不同的加速時(shí)間如下表。i05.175.435.836.016.176.33t（ s）26.267326.451625.898625.530025.161324.79262. 計(jì)算六工況百公里油耗。n=600:1:4000;m=3880;g=9.8;G=m*g; i0=6.01;ig=5.56 2.769 1.644 1.00 0.793;nT=0.85;r=0.367;f=0.013;CDA=2.77;L=3.2;a=1.947;hg=0.9;lf=0.218;lw1= 1.798;Iw2=3.598;

11、n0=815 1207 1614 2012 2603 3006 3403 3804;B00=1326.8 1354.7 1284.4 1122.9 1141.0 1051.2 1233.9 1129.7;B10=-416.46-303.98-189.75-121.59-98.893-73.714-84.478-45.291;B20=72.379 36.657 14.524 7.0035 4.4763 2.8593 2.9788 0.71113;B30=-5.8629 -2.0553 -0.51184-0.18517-0.091077-0.05138 -0.047449-0.00075215;B

12、40=0.177680.0430720.00681640.00185550.000689060.000350320.00028230 -0.000038568;BO=spline(n0,B00,n); B1=spline(nO,B1O,n);B2=spline(n0,B20,n); B3=spline(n0,B30,n);B4=spli ne(n 0,B40, n);Ff=G*f;ua5=0.377*r* n/ig (5)/i0;Fz5=Ff+CDA*(ua592)/21.15;Pe5=Fz5.*ua5./( nT*3.6*1000);for i=1:1:3401b5(i)=B0(i)+B1(

13、i)*Pe5(i)+B2(i)*Pe5(i).A2+B3(i)*Pe5(i).A3+B4(i)*Pe 5(i).A4;endpg=6.86;Qt5=Pe5.*b5/(367*pg);plot(ua5,Qt5);holdon ;axis(0 100 0 15);title( 油耗曲線);xlabel( ua(km/h) );ylabel(單位時(shí)間油耗ml/s);for i=20:1:50y(i)= in terp1(ua5,Qt5,i,cubic ） %插值（立方）不同速度下單位時(shí)間油耗enddt1=16.7/15; %每加速一公里時(shí)間dt2=14/10;y1=y(26)y(27)y(28)y(

14、29)y(30)y(31)y(32)y(33)y(34)y(35)y(36)y(37) y(38) y(39)y2=y(41) y(42) y(43) y(44) y(45) y(46) y(47) y(48) y(49)qd=19.3*0.299;%怠速油耗qj1=0.5*(y(25)+y(40)*dt1+sum(y1,2)*dt1;qj2=0.5*(y(40)+y(50)*dt2+sum(y2,2)*dt2;%加速段油耗qy=y(25)*7.2+y(40)*22.5+y(50)*18;%勻速段油耗qz仁(qd+qj1+qj2+qy)*100/1.075%總油耗，1.075為六工況下的行駛距

15、離.改變iO的值(取六個(gè)不同的值)分別求得各自百公里油耗如下表。i05.175.435.836.016.176.33Q( L)10.439L10.615L10.89L11.013L11.122L11.232L3. 繪制燃油經(jīng)濟(jì)性-加速時(shí)間曲線。q=10.439 10.615 10.753 10.89 11.013 11.122 11.232;t= 25.8986 25.8986 26.0829 25.8986 25.5300 25.3456 24.7926 ; plot(q,t, +r);hold onq1=li nspace(q(1),q(6),100);t1=spli ne(q,t,q1)

16、;%三次樣條插值plot(q1,t1);%繪制燃油經(jīng)濟(jì)性-加速時(shí)間曲線title(燃油經(jīng)濟(jì)性一加速時(shí)間曲線);xlabel(百公里油耗(L/100km);ylabel(加速時(shí)間s);gtext(i0=5.17),gtext(i0=5.43),gtext(i0=5.83)gtext(i0=6.01),gtext(i0=6.17),gtext(i0=6.33)已昭臥舊銘T凰目| 四燃油經(jīng)濟(jì)性一加速時(shí)間曲線6 45_5.一2 2-82424610.5o._-1.6o.110.710.810.91111.111.211.311.4百公里油耗(L/100krri)4計(jì)算最咼車速n=600:10:4000

17、;Tq=-19.313+295.27*(n000)-165.44*( n/1000)92+40.874* (n000)43- 3.8445* (n/1000).A4;%擬合公式m=3880;g=9.8; nmin=600; nm ax=4000;G=m*g;ig=5.56,2.769,1.644,1.00,0.793; nT=0.85;r=0.367;f=0.013;CDA=2.77;i0=5.83;L=3.2;a=1.947;hg=0.9;lf=0.218;lw 仁1.798;lw2=3.598;Ft仁 Tq*ig(1)*i0* nT/r;Ft2=Tq*ig (2) *i0* nT/r;Ft

18、3=Tq*ig (3) *i0* nT/r;Ft4=Tq*ig (4) *i0* nT/r;Ft5=Tq*ig (5) *i0* nT/r;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;ua=0:5:120;Ff=G*f;Fw=CDA*ua92/21.15;Fz=Ff+Fw;plot(ua1,Ft1,ua2,Ft2,ua3,Ft3,ua4,Ft4,ua5,Ft5,ua,Fz);title(驅(qū)動(dòng)力

19、-行駛阻力平衡圖);xlabel(ua(km/s);ylabel(Ft(N);gtext(Ft1 ),gtext(Ft2),gtext(Ft3),gtext(Ft4 ),gtext(Ft5),gtext(Ff+Fw);zoomon ;x,y=ginput(1);zoomoff5disp(汽車最咼車速=);disp(x);disp(km/h);-J怎% % U:必U LI 回驅(qū)動(dòng)力行駛阻力平衡團(tuán)uatkm/s)改變iO的值，求得相應(yīng)iO下的最高車速（iO為5.17,5.43時(shí)最高車速出現(xiàn)在第四檔）如下.i05.175.435.836.016.176.33umax102.354101.69299.074100.208101.115102.0235.繪制i0-umax曲線(求最高車速約束條件下臨界i0值)i0=5.17 5.43 5.83 6.01 6.17 6.33;umax=102.3535 101.6919 99.0737 100.2079 101.1153 102.0227;plot(i0,umax, +r );hold oniO1=li nspace(i0(1),i0(6),100);umax 仁 spli ne(iO,umax,iO1);%三次樣條插值plot(i01,umax1);% axis=5