ex7_17.m

反馈控制系统设计与分析（matlab程序）

G=tf(10,[1,10,35,50,24]);
[Kc,pm,wc,wm]=margin(G); Tc=2*pi/wc;
kappa=dcgain(G)*Kc;
[k,L,T]=getfod(G); N=10;
vars=[k,L,T,N,Kc,Tc,kappa];
[Gc,Kp,Ti,Td,H]=optPID(3,1,vars); [Kp,Ti,Td]

G_c=feedback(G*Gc,1);
step(G_c), 
figure, ngrid('new'); nichols(G*Gc); axis([-360,0,-40,40])