PID学习代码（二）

kp:

clear all;
close all;
figcount = 3;
kpvalue = [20 50 100];
for kpin = 1:figcount
    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=1:1:2000
        time(k)=k*ts;
        S=2;
        if S==1
            kp=10;ki=0.1;kd=15;
            rin(k)=5;                       %Step Signal
        elseif S==2
            %kp=20;ki=0.0;kd=0;          %Sine Signal
            kp=kpvalue(kpin);ki=0.1;kd=15;          %Sine Signal
            rin(k)=0.5*cos(2*pi*k*ts);
        end
        du(k)=kp*x(1)+kd*x(2)+ki*x(3);    %PID Controller
        u(k)=u_1+du(k);
        %Restricting the output of controller
        if u(k)>=5
            u(k)=5;
        end
        if u(k)<=-5
            u(k)=-5;
        end
        %Linear model
        yout(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 parameters
        u_2=u_1;u_1=u(k);
        y_2=y_1;y_1=yout(k);
        x(1)=error(k)-error_1;          %Calculating P
        x(2)=error(k)-2*error_1+error_2;   %Calculating D
        x(3)=error(k);      %Calculating I
        error_2=error_1;
        error_1=error(k);
    end
%     figure(1);
    subplot(figcount,1,kpin);
    plot(time,rin,'b',time,yout,'r');
    title(['kp=' num2str(kp) ',ki=0.1,kd=15'],'FontSize',14,'Color','k');
    xlabel('time(s)'),ylabel('rin,yout');
    legend('real value','estimate value');
%     title('函数y = xlogx','Color','k','FontSize',30);
%     figure(2);
%     plot(time,error,'r')
%     xlabel('time(s)');ylabel('error');
end

scrsz = get(0,'ScreenSize');
set(gcf,'Position',scrsz);
set(1, 'InvertHardCopy', 'off');%设置的背景色有效,如果为on则图形不保存背景色，maltab 默认为 on
saveas(1,'pid_pk_large','png');

运行结果：

ki:

clear all;
close all;
figcount = 3;
kivalue = [0.05 0.1 0.5];
kivalue = [1 2 10];
for kpin = 1:figcount
    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=1:1:2000
        time(k)=k*ts;
        S=2;
        if S==1
            kp=10;ki=0.1;kd=15;
            rin(k)=5;                       %Step Signal
        elseif S==2
            %kp=20;ki=0.0;kd=0;          %Sine Signal
            kp=10;ki=kivalue(kpin);kd=15;          %Sine Signal
            rin(k)=0.5*cos(2*pi*k*ts);
        end
        du(k)=kp*x(1)+kd*x(2)+ki*x(3);    %PID Controller
        u(k)=u_1+du(k);
        %Restricting the output of controller
        if u(k)>=5
            u(k)=5;
        end
        if u(k)<=-5
            u(k)=-5;
        end
        %Linear model
        yout(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 parameters
        u_2=u_1;u_1=u(k);
        y_2=y_1;y_1=yout(k);
        x(1)=error(k)-error_1;          %Calculating P
        x(2)=error(k)-2*error_1+error_2;   %Calculating D
        x(3)=error(k);      %Calculating I
        error_2=error_1;
        error_1=error(k);
    end
%     figure(1);
    subplot(figcount,1,kpin);
    plot(time,rin,'b',time,yout,'r');
    title([ ',kp=10,ki=' num2str(ki) ',kd=15'],'FontSize',14,'Color','k');
    xlabel('time(s)'),ylabel('rin,yout');
    legend('real value','estimate value');
%     title('函数y = xlogx','Color','k','FontSize',30);
%     figure(2);
%     plot(time,error,'r')
%     xlabel('time(s)');ylabel('error');
end

scrsz = get(0,'ScreenSize');
set(gcf,'Position',scrsz);
set(1, 'InvertHardCopy', 'off');%设置的背景色有效,如果为on则图形不保存背景色，maltab 默认为 on
saveas(1,'pid_pi','png');

运行结果：

kd:

clear all;
close all;
figcount = 3;
kdvalue = [1 5 10 ];
kdvalue = [15 100 1000];
for kpin = 1:figcount
    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=1:1:2000
        time(k)=k*ts;
        S=2;
        if S==1
            kp=10;ki=0.1;kd=15;
            rin(k)=5;                       %Step Signal
        elseif S==2
            %kp=20;ki=0.0;kd=0;          %Sine Signal
            kp=10;ki= 0.1;kd=kdvalue(kpin);          %Sine Signal
            rin(k)=0.5*cos(2*pi*k*ts);
        end
        du(k)=kp*x(1)+kd*x(2)+ki*x(3);    %PID Controller
        u(k)=u_1+du(k);
        %Restricting the output of controller
        if u(k)>=5
            u(k)=5;
        end
        if u(k)<=-5
            u(k)=-5;
        end
        %Linear model
        yout(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 parameters
        u_2=u_1;u_1=u(k);
        y_2=y_1;y_1=yout(k);
        x(1)=error(k)-error_1;          %Calculating P
        x(2)=error(k)-2*error_1+error_2;   %Calculating D
        x(3)=error(k);      %Calculating I
        error_2=error_1;
        error_1=error(k);
    end
%     figure(1);
    subplot(figcount,1,kpin);
    plot(time,rin,'b',time,yout,'r');
    title([ ',kp=10,ki=0.1,kd=' num2str(kd) ],'FontSize',14,'Color','k');
    xlabel('time(s)'),ylabel('rin,yout');
    legend('real value','estimate value');
%     title('函数y = xlogx','Color','k','FontSize',30);
%     figure(2);
%     plot(time,error,'r')
%     xlabel('time(s)');ylabel('error');
end

scrsz = get(0,'ScreenSize');
set(gcf,'Position',scrsz);
set(1, 'InvertHardCopy', 'off');%设置的背景色有效,如果为on则图形不保存背景色，maltab 默认为 on
saveas(1,'pid_kd_large','png');

执行结果：

PID demo：

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=1:1:2000
    time(k)=k*ts;
    S=1;
    if S==1
        kp=10;ki=0.1;kd=15;
        rin(k)=5;                       %Step Signal
    elseif S==2
        %kp=20;ki=0.0;kd=0;          %Sine Signal
         kp=10;ki=0.1;kd=15;          %Sine Signal
        rin(k)=0.5*cos(2*pi*k*ts);
    end
    du(k)=kp*x(1)+kd*x(2)+ki*x(3);    %PID Controller
    u(k)=u_1+du(k);
    %Restricting the output of controller
    if u(k)>=5
        u(k)=5;
    end
    if u(k)<=-5
        u(k)=-5;
    end
    %Linear model
    yout(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 parameters
    u_2=u_1;u_1=u(k);
    y_2=y_1;y_1=yout(k);
    x(1)=error(k)-error_1;          %Calculating P
    x(2)=error(k)-2*error_1+error_2;   %Calculating D
    x(3)=error(k);      %Calculating I
    error_2=error_1;
    error_1=error(k);
end
figure(1);
plot(time,rin,'b',time,yout,'r');
xlabel('time(s)'),ylabel('rin,yout');
title(['kp=10,ki=0.1,kd=15'],'FontSize',14,'Color','k');
saveas(1,'pid_const','png');
figure(2);
plot(time,error,'r')
title(['误差变化'],'FontSize',14,'Color','k');
xlabel('time(s)');ylabel('error');
saveas(2,'pid_const_err','png');

执行结果：