ttt.m

文件是编辑好的m文件

G1=tf([1],[7.5 1]);G2=tf([1],[30 1]);G3=tf([1],[60 1]);G=G1*G2*G3;
[Gmm,Pmm,Wcgm,Wcpm]=freqm(G,0.221,'margin');
figure('pos',[30,50,250,250],'color','w'); axes('pos',[0.2,0.2,.7,.7]);
GC=feedback(Gmm*G,1);step(GC);Gmm
set(gca,'ytick',[0:.5:1,1.1:.1:1.5],'ygrid','on');