我用了刘金琨《先进PID》控制中基于实数编码PID整定的例子改了传递函数参数后(sys=tf(400,[1,50,0]);变为sys=tf(12.5,[1,2.58,12.5]); )整定后的阶跃响应图形变为

[img]file:///C:\Users\leglas\AppData\Roaming\Tencent\Users\76744502\QQ\WinTemp\RichOle\R`G_U{1O[H{`DCQT}Y)O%BA.jpg[/img]

想请教下大家是怎么回事呢？

谢咯！

附程序

%GA(Generic Algorithm) Program to optimize PID Parameters

clear all;

close all;

global rin yout timef

Size=30;

CodeL=3;

MinX(1)=zeros(1);

MaxX(1)=20*ones(1);

MinX(2)=zeros(1);

MaxX(2)=1.0*ones(1);

MinX(3)=zeros(1);

MaxX(3)=1.0*ones(1);

Kpid(:,1)=MinX(1)+(MaxX(1)-MinX(1))*rand(Size,1);

Kpid(:,2)=MinX(2)+(MaxX(2)-MinX(2))*rand(Size,1);

Kpid(:,3)=MinX(3)+(MaxX(3)-MinX(3))*rand(Size,1);

G=100;

BsJ=0;

%*************** Start Running ***************

for kg=1:1:G

time(kg)=kg;

%****** Step 1 : Evaluate BestJ ******

for i=1:1:Size

Kpidi=Kpid(i,:);

[Kpidi,BsJ]=chap5_3f(Kpidi,BsJ);

BsJi(i)=BsJ;

end

[OderJi,IndexJi]=sort(BsJi);

BestJ(kg)=OderJi(1);

BJ=BestJ(kg);

Ji=BsJi+1e-10;    %Avoiding deviding zero

fi=1./Ji;

%  Cm=max(Ji);

%  fi=Cm-Ji;

[Oderfi,Indexfi]=sort(fi);    %Arranging fi small to bigger

Bestfi=Oderfi(Size);          %Let Bestfi=max(fi)

BestS=Kpid(Indexfi(Size),:);  %Let BestS=E(m), m is the Indexfi belong to max(fi)

kg

BJ

BestS

%****** Step 2 : Select and Reproduct Operation******

fi_sum=sum(fi);

fi_Size=(Oderfi/fi_sum)*Size;

fi_S=floor(fi_Size);                    % Selecting Bigger fi value

r=Size-sum(fi_S);

Rest=fi_Size-fi_S;

[RestValue,Index]=sort(Rest);

for i=Size:-1:Size-r+1

fi_S(Index(i))=fi_S(Index(i))+1;     % Adding rest to equal Size

end

k=1;

for i=Size:-1:1       % Select the Sizeth and Reproduce firstly

for j=1:1:fi_S(i)

TempE(k,:)=Kpid(Indexfi(i),:);      % Select and Reproduce

k=k+1;                            % k is used to reproduce

end

end

%************ Step 3 : Crossover Operation ************

Pc=0.90;

for i=1:2:(Size-1)

temp=rand;

if Pc>temp                      %Crossover Condition

alfa=rand;

TempE(i,:)=alfa*Kpid(i+1,:)+(1-alfa)*Kpid(i,:);

TempE(i+1,:)=alfa*Kpid(i,:)+(1-alfa)*Kpid(i+1,:);

end

end

TempE(Size,:)=BestS;

Kpid=TempE;

%************ Step 4: Mutation Operation **************

Pm=0.10-[1:1:Size]*(0.01)/Size;       %Bigger fi,smaller Pm

Pm_rand=rand(Size,CodeL);

Mean=(MaxX + MinX)/2;

Dif=(MaxX-MinX);

for i=1:1:Size

for j=1:1:CodeL

if Pm(i)>Pm_rand(i,j)        %Mutation Condition

TempE(i,j)=Mean(j)+Dif(j)*(rand-0.5);

end

end

end

%Guarantee TempE(Size,:) belong to the best individual

TempE(Size,:)=BestS;

Kpid=TempE;

end

Bestfi

BestS

Best_J=BestJ(G)

figure(1);

plot(time,BestJ);

xlabel('Times');ylabel('Best J');

figure(2);

plot(timef,rin,'r',timef,yout,'b');

xlabel('Time(s)');ylabel('rin,yout');

function [Kpidi,BsJ]=pid_gaf(Kpidi,BsJ)

global rin yout timef

ts=0.001;

sys=tf(12.5,[1,2.58,12.5]);

dsys=c2d(sys,ts,'z');

[num,den]=tfdata(dsys,'v');

rin=1.0;

u_1=0.0;u_2=0.0;

y_1=0.0;y_2=0.0;

x=[0,0,0]';

B=0;

error_1=0;

tu=1;

s=0;

P=100;

for k=1:1:P

timef(k)=k*ts;

r(k)=rin;

u(k)=Kpidi(1)*x(1)+Kpidi(2)*x(2)+Kpidi(3)*x(3);

if u(k)>=10

u(k)=10;

end

if u(k)<=-10

u(k)=-10;

end

yout(k)=-den(2)*y_1-den(3)*y_2+num(2)*u_1+num(3)*u_2;

error(k)=r(k)-yout(k);

%------------ Return of PID parameters -------------

u_2=u_1;u_1=u(k);

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_2=error_1;

error_1=error(k);

if s==0

if yout(k)>0.95&yout(k)<1.05

tu=timef(k);

s=1;

end

end

end

for i=1:1:P

Ji(i)=0.999*abs(error(i))+0.01*u(i)^2*0.1;

B=B+Ji(i);

if i>1

erry(i)=yout(i)-yout(i-1);

if erry(i)<0

B=B+100*abs(erry(i));

end

end

end

BsJ=B+0.2*tu*10;[img]file:///C:\Users\leglas\AppData\Roaming\Tencent\Users\76744502\QQ\WinTemp\RichOle\R`G_U{1O[H{`DCQT}Y)O%BA.jpg[/img]

20130722100031.jpg

(20.99 KB, 下载次数: 34)

2013-7-22 10:00 上传