ex7_4.m

反馈控制系统设计与分析（matlab程序）

G=tf(10, conv([1,1],conv([1,2],conv([1,3],[1,4]))));
step(G); k=dcgain(G)
L=0.76; T=2.72-L;  
[Gc1,Kp1]=ziegler(1,[k,L,T,10]); Kp1
[Gc2,Kp2,Ti2]=ziegler(2,[k,L,T,10]); [Kp2,Ti2]
[Gc3,Kp3,Ti3,Td3]=ziegler(3,[k,L,T,10]); [Kp3,Ti3,Td3]
G_c1=feedback(G*Gc1,1); step(G_c1); hold on
G_c2=feedback(G*Gc2,1); step(G_c2); 
G_c3=feedback(G*Gc3,1); step(G_c3);