% Figure 9.15 Feedback Control of Dynamic Systems, 4e
% Franklin, Powell, Emami
%
% fig9_15.m is a script to generate Fig 9.15
% the root locus of the PD plus notch compensator of the
% satellite position control, non-colocated case with the stiff-spring
% parameters
m=[1, 0.1] ; k1 = [0, 0.4] ; b1=[0, 0.04*sqrt(0.04)];
% call function
[f,g,h,j]=twomass(m,k1,b1);
no3=conv(.25*[2 1],[1/.81 0 1]);
do3=conv([1/40 1],[1/625 2/25 1]);
[Ac3,Bc3,Cc3,Dc3]=tf2ss(no3,do3);
[Aol,Bol,Col,Dol]=series( Ac3,Bc3,Cc3,Dc3, f,g,h,j);
[Acl]=[Aol-Bol*Col];
hold off; clf
v=[-8, 1, -3, 3];axis(v);
pzmap(Aol,Bol,Col,Dol);
hold on;
k1=[0:.1:1.4];
k2=[1.4:.001:1.5];
k3=[1.5:.001:1.6];
k4=[1.6:.001:1.7];
k5=[1.7:.5:50];
r=rlocus(Aol,Bol,Col,Dol,k1);
plot(r,'-')
r=rlocus(Aol,Bol,Col,Dol,k2);
plot(r,'-')
r=rlocus(Aol,Bol,Col,Dol,k3);
plot(r,'-')
r=rlocus(Aol,Bol,Col,Dol,k4);
plot(r,'-')
r=rlocus(Aol,Bol,Col,Dol,k5);
plot(r,'-')
grid;
v=[-8,1,-3,3];
axis(v);
title('Rootlocus for KD3(s)Ghat(s)')
