<MATLAB 7辅助控制系统设计与仿真>书籍内的源代码.

				% 设计P、PI、PID控制器
				G=tf(10,[1,10,35,50,24]);
				[k,L,T]=getfod(G);
				[Gc1,Kp1]=cohen(1,[k,L,T,10]);[Kp1]
				[Gc2,Kp2,Ti2]=cohen(2,[k,L,T,10]);[Kp2,Ti2]
				[Gc3,Kp3,Ti3,Td3]=cohen(3,[k,L,T,10]);[Kp3,Ti3,Td3]
				[Gc4,Kp4,Ti4,Td4]=cohen(4,[k,L,T,10]);[Kp4,Td4]
				t=0:0.1:10;
				G_c1=feedback(G*Gc1,1);y=step(G_c1,t);
				G_c2=feedback(G*Gc2,1);y=[y step(G_c2,t)];
				G_c3=feedback(G*Gc3,1);y=[y step(G_c3,t)];
				G_c4=feedback(G*Gc4,1);y=[y step(G_c4,t)];
				plot(t,y)