ex4_20.m

反馈控制系统设计与分析（matlab程序）

G1=tf([5,100],[1,8,32,80,100]); G=ss(G1);
u0=[2,-1,-24]; Y0=[0.3; 0.5; 0; 0];
hatY0=Y0-[0; G.c*G.b*u0(1); 
     G.c*G.b*u0(2)+G.c*G.a*G.b*u0(1); 
     G.c*G.b*u0(3)+G.c*G.a*G.b*u0(2)+G.c*G.a^2*G.b*u0(1)];
Wo=obsv(G); X0=inv(Wo)*hatY0;  
t=0:.04:4; u=1+exp(-t).*cos(5*t);
y1=lsim(G,u,t); % zero-state response evaluation
y2=initial(ss(G),X0,t); % zero-state evaluation
y=y1+y2; plot(t,u), figure
plot(t,y2,':', t,y1,'--', t,y,'-')