反馈控制系统分析与设计,虽然有点抽象

				G=tf(1,[1,3,3,1]); N=10; Tdly=1; 
				[nP,dP]=pade(Tdly,3); G_o=G*tf(nP,dP);
				[k,L,T]=getfod(G_o); 
				t1=0; t2=0; tend=50; U=1;
				[Gc1,Kp,Ti,Td]=ziegler(3,[k,L,T,N]); [Kp,Ti,Td]
				
				G_c=feedback(G_o*Gc1,1); 
				step(G_c); hold on
				num=G.num{1}; den=G.den{1}; 
				[tt1,x,yy1]=sim('c7fsimd',tend,[]); plot(tt1,yy1)
				
				[Kc,p,wc,w]=margin(G_o); Tc=2*pi/wc;
				[Gc1,Kp,Ti,Td]=ziegler(3,[Kc,Tc,N]); [Kp,Ti,Td]
				
				G_c=feedback(G_o*Gc1,1); step(G_c); hold on
				[tt2,x,yy2]=sim('c7fsimd',tend,[]); plot(tt2,yy2)