gaijin.m

基于matlab的PID控制系统仿真

clear all;close all;

%Delay plant
kp1=20;%假设系统参数
Tp=500;
tol=2; 
Ts=tol/4;
ts=tol/4;
sys=tf([kp1],[Tp,1],'inputdelay',tol);
dsys=c2d(sys,Ts,'zoh');
[num,den]=tfdata(dsys,'v');

u_1=0.0;u_2=0.0;u_3=0.0;u_4=0.0;u_5=0.0;
xm_1=0.0;
ym_1=0.0;
y_1=0.0;
error_1=0;
ei=0;                        %定义初始值
for k=1:1:1000
  time(k)=k*ts;
  
if k<500
  rin(k)=80;
else rin(k)=80;
  end                        %假设的两个阶越输入

 %Prediction model
 xm(k)=-den(2)*xm_1+num(2)*u_1;
 ym(k)=-den(2)*ym_1+num(2)*u_5;  %With Delay 运用SMITH模型

yout(k)=-den(2)*y_1+num(2)*u_5;
error(k)=rin(k)-xm(k);  
derror(k)=(error(k)-error_1)/ts; 


ap=0.13*(80/tol)^1.2/(Tp/1000)^1.3*100/kp1;
bp=0.07*(80/tol)^1.2/(Tp/1000)^1.3*100/kp1;
cp=0.8;
kp(k)=ap+bp*(1-sech(cp*error(k)));

ad=0.5*(tol/80)^2;bd=2.35*(tol/80)^2;cd=1.2;dd=2.0;
kd(k)=ad+bd/(1+cd*exp(dd*error(k)));

ai=0.005*(80/tol)^0.624/(Tp/1000)^3;ci=0.04*(80/tol)^0.624;
ki(k)=ai*sech(ci*error(k));              %参数变化规率及初始植

ei=ei+error(k)*ts;
u(k)=kp(k)*error(k)+kd(k)*derror(k)+ki(k)*ei;

xm_1=xm(k);
ym_1=ym(k);

u_5=u_4;u_4=u_3;u_3=u_2;u_2=u_1;u_1=u(k);
y_1=yout(k);
error_1=error(k);
end

figure(1);
plot(time,rin,'k',time,yout,'k');
xlabel('time(s)');ylabel('rin,yout');

figure(2);
plot(time,error,'k');
xlabel('time(s)');ylabel('error');