fig919.m

realize analysis and design for computer-controlled system

% Generates Fig 9.19
% Computer Controlled Systems (3rd ed)
% Author: B. Wittenmark
% Last edit: 1997-07-09
% Copyright (c) 1996 by K. J. 舠tr鰉, B. Wittenmark and
% Department of Automatic Control, Lund Institute of
% Technology, Lund, Sweden

newplot;
set(gcf,'PaperUnits','centimeters','PaperPosition',[2 2 13 10])
set(gcf,'Units','centimeters','position',get(gcf,'PaperPosition'))

lw=0.9;
sig=7;
ts=1000;
al=[-0.9 -0.97 -0.98 -0.99];
newplot;clf;
hold on
for k=1:4,
a=al(k);
b=1+a;
a1=4*a;
a2=6*a*a;
a3=4*a*a*a;
a4=a*a*a*a;
Ac=chop([-a1 -a2 -a3 -a4;1 0 0 0;0 1 0 0;0 0 1 0],sig);
Bc=chop([1;0;0;0],sig);
Cc=chop([b*b*b*b 0 0 0],sig);
xc=[0;0;0;0];
yc=zeros(ts,1);
%
Aj=chop([-a b 0 0;0 -a b 0;0 0 -a b;0 0 0 -a],sig);
Bj=chop([0;0;0;b],sig);
Cj=chop([1 0 0 0],sig);
xj=[0;0;0;0];
yj=zeros(ts,1);
%
b1=4*b;
b2=6*b*b;
b3=4*b*b*b;
b4=b*b*b*b;
Ad=chop([1-b1 -b2 -b3 -b4;1 1 0 0;0 1 1 0;0 0 1 1],sig);
Bd=chop([1;0;0;0],sig);
Cd=chop([0 0 0 b*b*b*b],sig);
xd=[0;0;0;0];
yd=zeros(ts,1);
%
for i=1:ts,
xc=chop(chop(Ac*xc,sig)+Bc,sig);yc(i)=chop(Cc*xc,sig);
xj=chop(chop(Aj*xj,sig)+Bj,sig);yj(i)=chop(Cj*xj,sig);
xd=chop(chop(Ad*xd,sig)+Bd,sig);yd(i)=chop(Cd*xd,sig);
end
subplot(3,2,k);
plot(yc,'k--','Linew',lw);
hold on;
plot(yd,'m-','Linew',lw);
plot(yj,'g-.','Linew',lw);
axis([0 ts 0 1.2]);
set(gca,'FontSize',9,'Fontname','NewCenturySchlbk')
set(gca,'xtick',[0 500 1000]);
set(gca,'ytick',[0 1]);
ylabel('Output','Fontname','NewCenturySchlbk','Fontsize',9)
drawnow;
end
%
subplot(3,2,1)
text(-250,1.2,'(a)','Fontname','NewCenturySchlbk','Fontsize',9)
subplot(3,2,2)
text(-250,1.2,'(b)','Fontname','NewCenturySchlbk','Fontsize',9)
subplot(3,2,3)
text(-250,1.2,'(c)','Fontname','NewCenturySchlbk','Fontsize',9)
xlabel('Time','Fontname','NewCenturySchlbk','Fontsize',9)
subplot(3,2,4)
text(-250,1.2,'(d)','Fontname','NewCenturySchlbk','Fontsize',9)
xlabel('Time','Fontname','NewCenturySchlbk','Fontsize',9)