【动力学】汽车性能仿真系统含Matlab源码-CFANZ编程社区

【动力学】汽车性能仿真系统含Matlab源码

1 简介

汽车性能仿真实验

2 部分代码

global M1 M2 M g r nt f CDA io If Iw1 Iw2 ig i1 i2 i3 i4 L a hg nmax nmin tmax imax;
g=9.81;
uamin=10;
uamax1=70;
n=nmin:(nmax-nmin)/9:nmax;
n0=n/1000;
tq=-19.313+295.27.*(n0)-165.44.*(n0.^2)+40.874.*(n0.^3)-3.8445.*(n0.^4);
ft0=tq.*io.*nt./r;
ft1=ft0.*i1;
ft2=ft0.*i2;
ft3=ft0.*i3;
ft4=ft0.*i4;
ua1=0.377.*r.*n./(i1.*io);
ua2=0.377.*r.*n./(i2.*io);
ua3=0.377.*r.*n./(i3.*io);
ua4=0.377.*r.*n./(i4.*io);
fw1=CDA.*(ua1.^2)./21.15;
fw2=CDA.*(ua2.^2)./21.15;
fw3=CDA.*(ua3.^2)./21.15;
fw4=CDA.*(ua4.^2)./21.15;
Iw=Iw1+Iw2;
da0=1+Iw./(M.*(r.^2)); 
da01=(io.^2).*nt.*If./(M.*(r.^2));
da1=da0+da01.*(i1.^2);
da2=da0+da01.*(i2.^2);
da3=da0+da01.*(i3.^2);
da4=da0+da01.*(i4.^2);
ff=M.*g.*f;
a1=(ft1-ff-fw1)./(da1.*M);
a2=(ft2-ff-fw2)./(da2.*M);
a3=(ft3-ff-fw3)./(da3.*M);
a4=(ft4-ff-fw4)./(da4.*M);
js1=1./a1;
js2=1./a2;
js3=1./a3;
js4=1./a4;
t1=js1(1:end-1).*(ua1(2:end)-ua1(1:end-1));
ii=1;
while ua2(ii)<=ua1(end)
    ii=ii+1;
     ua2(ii)=ua2(ii+1);
 end
t2=js2(ii:end-1).*(ua2(ii+1:end)-ua2(ii:end-1));
t12=js2(ii).*(ua2(ii)-ua1(end));
jj=1;
while ua3(jj)<=ua2(end)
    jj=jj+1;
     ua3(jj)=ua3(jj+1);
 end
t3=js3(jj:end-1).*(ua3(jj+1:end)-ua3(jj:end-1));
t23=js3(jj).*(ua3(jj)-ua2(end));
kk=1;
while ua4(kk)<=ua3(end)
    kk=kk+1;
     ua4(kk)=ua4(kk+1);
 end
t4=js4(kk:end-1).*(ua4(kk+1:end)-ua4(kk:end-1));
t34=js4(kk).*(ua4(kk)-ua3(end));
T1=[t1 t2 t3 t4];
T=sum((T1)+t12+t23+t34);   %总时间
Ua=[ua1(1:end-1) ua2(ii:end-1) ua3(jj:end-1) ua4(kk:end-1)];
x=T1;
y=Ua;
p3=polyfit(x,y,2);
ppp=[ p3(1) p3(2)   p3(3)-uamax1]; % 求70km/h时的时间
TT=roots(ppp);
tmax=min(TT);
xc=0:1:60;
p3c=polyval(p3,xc);
plot(T1,Ua,'*',xc,p3c);
xlabel('时间t/s','FontSize',8)
ylabel('速度ua/（km/h）','FontSize',8)
title('汽车加速时间曲线','FontSize',12)
grid on;
legend('各阶段加速度','拟合曲线',4);