lisaxitongshuzifangzhen.m

离散系统的数字PID仿真:针对离散系统的阶跃信号、正弦信号和方波信号的位置响应

clear all;
close all;

ts=0.001;
sys=tf(5.23e005,[1,87.35,1.047e004,0]);
dsys=c2d(sys,ts,'z');
[num,den]=tfdata(dsys,'v');
  

u_1=0.0;u_2=0.0;u_3=0.0;
y_1=0.0;y_2=0.0;y_3=0.0;
x=[0,0,0]';
error_1=0;

for k=1:1:1500
    time(k)=k*ts;
 s=3;
 if s==1
     kp=0.50;ki=0.001;kd=0.001;
      rin(k)=1;                       %step signal
 elseif s==2
     kp=0.50;ki=0.001;kd=0.001;
     rin(k)=sign(sin(2*2*pi*k*ts));    %square wave signal
 elseif  s==3
     kp=1.5;ki=1.0;kd=0.01;
     rin(k)=0.5*sin(2*2*pi*k*ts);
 end
 
 
 u(k)=kp*x(1)+kd*x(2)+ki*x(3);      %pid  control
 
 if u(k)>=10
     u(k)=10;
 end
 if u(k)<=-10
     u(k)=-10;
 end
 %linear model
  yout(k)=-den(2)*y_1-den(3)*y_2-den(4)*y_3+num(2)*u_1+num(3)*u_2+num(4)*u_3;
  
  error(k)=rin(k)-yout(k);
  
  %return of parameters
  
  u_3=u_2;u_2=u_1;u_1=u(k);
  y_3=y_2;y_2=y_1;y_1=yout(k);
  
  x(1)=error(k);               %calculating P
  x(2)=(error(k)-error_1)/ts;  % calculating D
  x(3)=x(3)+error(k)*ts;       %calculating  I
  
  
  error_1=error(k);
end

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