chapter6_2.m

《MATLAB在控制系统中的应用》实例程序

ng0=[1];dg0=[1,6,5,0]; g0=tf(ng0,dg0); delta=0.02; Kc=-1; 
for Kp1=1:0.1:50; 
gt=feedback(Kp1*g0,1); 
P=roots(gt.den{1}); 
for i=1:1:length(P); 
if abs(real(P(i)))<=10*eps 
Kc=Kp1, Pc=2*pi/abs(imag(P(i))), 
break; 
end; 
end; 
if Kc>=0 
break; 
end; 
end; 
Kp=0.6*Kc, Ti=0.5*Pc, Td=0.125*Pc, 
ngc=Kp*[Ti*Td,Ti,1];dgc=[Ti,0]; 
gc=tf(ngc,dgc);zpk(gc), 
g=feedback(gc*g0,1); 
[pos,tr,ts,tp]=stepchar(g,delta); pos,ts, 
t=[0:0.001:1.5*ts]; step(g,t);grid on