ex6_20.m

华东理工大学自动化系《控制系统分析、设计和应用》教材配套程序实例,有关说明： 1. 安装MATLAB软件。安装时

% ex6_20
% Ziegler-Nichols法整定控制器参数
figure('pos',[100,100,200,180],'color','w');
k=1;t=10;tor=3; 
finalt=60;fs=0.01 ;step1=1;steps=num2str(step1);
G=tf(k,[t 1]);
set(G,'inputdelay',tor);
open_system('order11');
set_param('order11/R(s)','After',steps,'SampleTime','.1');
set_param('order11/F(s)','After','0','SampleTime','.1');
tors=num2str(tor);
ks=num2str(k);
ts=num2str(t);
set_param('order11/Gp(s)','Kp',ks,'Tp',ts,'tor',tors);
[Gc,kc,ti,td]=z_n1(k,t,tor,'pi'),
tds=num2str(td);
kcs=num2str(kc);
tis=num2str(ti);
set_param('order11/PID','Kc',kcs,'Ti',tis,'Td',tds);
open_system('order11/SC');
Op=simset('solver','ode4','fixed',step1,'FixedStep',fs);
[t,x,y]=sim('order11',[0 finalt],Op);
load c:\data.mat;
plot(t,out(2,:),'k' );
yM=max(out(2,:))*1.1;
ym=min(out(2,:));
if ym<0,
    ymm=1.1*ym, 
else 
    ymm=ym*0.9;
end;
axis([0 finalt ymm yM]);