增量式PID控制算法Matlab仿真程序

clear all;close all; ts=0.001;sys=tf(50,[0.125,7, 0]);dsys=c2d(sys,ts,'z');[num,den]=tfdata(dsys,'v'); u_1=0.0;u_2=0.0;y_1=0.0;y_2=0.0;x=[0,0,0]';error_1=0;error_2=0;for k=1:1:1000time(k)=k*ts;   S=2;if S==1    kp=10;ki=0.1;kd=15;              rin(k)=1;                       %Step Signalelseif S==2    kp=10;ki=0.1;kd=15;          %Sine Signal    rin(k)=0.5*sin(2*pi*k*ts);           end du(k)=kp*x(1)+kd*x(2)+ki*x(3);    %PID Controlleru(k)=u_1+du(k);%Restricting the output of controllerif u(k)>=5          u(k)=5;endif u(k)<=-5   u(k)=-5;end%Linear modelyout(k)=-den(2)*y_1-den(3)*y_2+num(2)*u_1+num(3)*u_2; error(k)=rin(k)-yout(k); %Return of parametersu_2=u_1;u_1=u(k);y_2=y_1;y_1=yout(k);   x(1)=error(k)-error_1;          %Calculating Px(2)=error(k)-2*error_1+error_2;   %Calculating Dx(3)=error(k);      %Calculating I error_2=error_1;error_1=error(k);endfigure(1);plot(time,rin,'b',time,yout,'r');xlabel('time(s)'),ylabel('rin,yout'); figure(2);plot(time,error,'r')xlabel('time(s)');ylabel('error');