8.3.m

来自「周克敏 鲁棒控制基础 （essential of robust control 」· M 代码 · 共 22 行

G0=tf(11,conv([1 1],[0.25 1]));
for tuo=0.001:0.05:0.5
    for K=10:0.1:12
        G=tf(K,conv([1 1],[tuo,1]));
        delta=minreal((G-G0)/G0);
        w=logspace(-2,2,100);
        [num,den]=tfdata(delta,'v');
        Gd=nd2sys(num,den);
        Gf=frsp(Gd,w);
        vplot('liv,lm',Gf);
        hold on;
    end
end
grid
mf=ginput(50);
magg=vpck(mf(:,2),mf(:,1));
figure(2)
Wa=fitmag(magg);
[A,B,C,D]=unpck(Wa);
[num,den]=ss2tf(A,B,C,D);
W=tf(num,den)