ex8_23.m

反馈控制系统设计与分析（matlab程序）

wn=[1,10,50,100]; 
for i=1:length(wn),  
   G1=std_tf(1,wn(i),3); 
   nW=G1.den{1}; dW=[G1.den{1}(1:3),0];
   [m,p,w]=bode(tf(nW,dW)); 
   semilogx(w,20*log10(m(:)')); hold on
end

num=[1,5]; den=[1,-2,4]; G=tf(num,den);
wn=[1,10,50,100];
[a,b,c,d]=tf2ss(num,den); S=mksys(a,b,c,d); 
for i=1:length(wn)
   G1=std_tf(1,wn(i),3); G2=1-G1; 
   w1=[G2.den{1};G2.num{1}]; w1(2,4)=0.001;
   TSS_=augtf(S,w1,[1e-5;1],[]);
   [gg,ss_F]=hinfopt(TSS_); [af,bf,cf,df]=branch(ss_F); 
   Gc=ss(af,bf,cf,df); G_c=feedback(G*Gc,1);
   step(G_c), hold on, pause
end
set(gca,'XLim',[0,1])

zpk(Gc)