www.pudn.com > chap1.rar > chap1_21.m

%PID Controler with differential in advance 
clear all; 
close all; 
 
ts=20; 
sys=tf([1],[60,1],'inputdelay',80); 
dsys=c2d(sys,ts,'zoh'); 
[num,den]=tfdata(dsys,'v'); 
 
u_1=0;u_2=0;u_3=0;u_4=0;u_5=0; 
ud_1=0; 
y_1=0;y_2=0;y_3=0; 
error_1=0;error_2=0; 
ei=0; 
for k=1:1:400 
time(k)=k*ts; 
 
%Linear model 
yout(k)=-den(2)*y_1+num(2)*u_5; 
 
kp=0.36;kd=14;ki=0.0021; 
 
rin(k)=1.0*sign(sin(0.00025*2*pi*k*ts)); 
rin(k)=rin(k)+0.05*sin(0.03*pi*k*ts); 
 
error(k)=rin(k)-yout(k); 
ei=ei+error(k)*ts; 
 
gama=0.50; 
Td=kd/kp; 
Ti=0.5; 
 
c1=gama*Td/(gama*Td+ts); 
c2=(Td+ts)/(gama*Td+ts); 
c3=Td/(gama*Td+ts); 
 
M=2; 
if M==1      %PID Control with differential in advance 
	ud(k)=c1*ud_1+c2*yout(k)-c3*y_1; 
	u(k)=kp*error(k)+ud(k)+ki*ei; 
elseif M==2  %Simple PID Control 
	u(k)=kp*error(k)+kd*(error(k)-error_1)/ts+ki*ei; 
end 
 
if u(k)>=110 
   u(k)=110; 
end 
if u(k)<=-110 
   u(k)=-110; 
end 
%Update parameters 
u_5=u_4;u_4=u_3;u_3=u_2;u_2=u_1;u_1=u(k); 
y_3=y_2;y_2=y_1;y_1=yout(k); 
    
error_2=error_1; 
error_1=error(k); 
end 
figure(1); 
plot(time,rin,'r',time,yout,'b'); 
xlabel('time(s)');ylabel('rin,yout'); 
figure(2); 
plot(time,u,'r'); 
xlabel('time(s)');ylabel('u');