num=[1,-1]; den=[1,2,1]; G=tf(num,den);
nW=0.62*[1,1.2,1]; dW=conv([1,0.001],conv([1,1.2],[0.001,1]));
[a,b,c,d]=tf2ss(num,den); S=mksys(a,b,c,d);
W1=[0,nW; dW]; TSS_1=augtf(S,W1,[],[]);
F1=hinf(TSS_1);

TSS_1=augtf(S,W1,[1e-5;1],[]);
F1=hinf(TSS_1);

[af,bf,cf,df]=branch(F1); Gc=zpk(ss(af,bf,cf,df))

G_o=G*Gc; G_c=feedback(G_o,1);
t=0:.1:10; step(G_c,t), 
figure, ngrid('new'), nichols(G_o), axis([-360,0,-40,40])