% Fig. 5.16   Feedback Control of Dynamic Systems, 8e 
%             Franklin, Powell, Emami
% 

clf

s=tf('s');

sysG = (((s+0.1)^2)+36)/((s^2)*(((s+0.1)^2)+(6.6)^2));
sysD = (s+1)/(s+12);

rlocus( sysG*sysD )

title(' Fig. 5.16 Root locus for collocated system')
axis([-15, 5, -8, 8])

z=0.1:.2:.9;
 wn=1:2:18;
 sgrid(z, wn)
 hold off 