ziegler.m

控制系统计算机辅助设计——MATLAB语言与应用(源代码）

function [Gc,Kp,Ti,Td,H]=ziegler(key,vars)
Ti=[]; Td=[]; H=1;
if length(vars)==4,
   K=vars(1); L=vars(2); T=vars(3); N=vars(4); a=K*L/T;
   if key==1,  Kp=1/a;
   elseif key==2, Kp=0.9/a; Ti=3.33*L;
   elseif key==3 | key==4, Kp=1.2/a; Ti=2*L; Td=L/2; end
elseif length(vars)==3,
   K=vars(1); Tc=vars(2); N=vars(3);
   if key==1, Kp=0.5*K;
   elseif key==2, Kp=0.4*K; Ti=0.8*Tc;
   elseif key==3 | key==4, Kp=0.6*K; Ti=0.5*Tc; Td=0.12*Tc; end
elseif length(vars)==5,
   K=vars(1); Tc=vars(2); rb=vars(3); N=vars(5);
   pb=pi*vars(4)/180; Kp=K*rb*cos(pb);
   if key==2, Ti=-Tc/(2*pi*tan(pb));
   elseif key==3 | key==4, Ti=Tc*(1+sin(pb))/(pi*cos(pb)); Td=Ti/4; end
end
switch key
case 1, Gc=Kp;
case 2, Gc=tf(Kp*[Ti,1],[Ti,0]);
case 3, 
   nn=[Kp*Ti*Td*(N+1)/N,Kp*(Ti+Td/N),Kp]; dd=Ti*[Td/N,1,0]; Gc=tf(nn,dd);
case 4,  
   d0=sqrt(Ti*(Ti-4*Td)); Ti0=Ti; Kp=0.5*(Ti+d0)*Kp/Ti; Ti=0.5*(Ti+d0); 
   Td=Ti0-Ti; Gc=tf(Kp*[Ti,1],[Ti,0]); nH=[(1+Kp/N)*Ti*Td,Kp*(Ti+Td/N),Kp]; 
   H=tf(nH,Kp*conv([Ti,1],[Td/N,1]));
case 5, Gc=tf(Kp*[Td*(N+1)/N,1],[Td/N,1]);
end