bpannpid.m

是一个神经网络PID控制例子,控制对象为一个直升机俯仰轴的角度控制,数学模型为二阶传递函数.

%BP based PID Control
clear all;
close all;

xite=0.1;
alfa=0.25;



IN=4;H=5;Out=3;  %NN Structure

wi=[-0.6394   -0.2696   -0.3756   -0.7023;
    -0.8603   -0.2013   -0.5024   -0.2596;
    -1.0749    0.5543   -1.6820   -0.5437;
    -0.3625   -0.0724   -0.6463   -0.2859;
     0.1425    0.0279   -0.5406   -0.7660];
%wi=0.50*rands(H,IN);
wi_1=wi;wi_2=wi;wi_3=wi;
wo=[0.7576 0.2616 0.5820 -0.1416 -0.1325;
   -0.1146 0.2949 0.8352  0.2205  0.4508;
    0.7201 0.4566 0.7672  0.4962  0.3632];
%wo=0.50*rands(Out,H);
wo_1=wo;wo_2=wo;wo_3=wo;




x=[0,0,0];
du_1=0;
u_1=0;u_2=0;u_3=0;u_4=0;u_5=0;
y_1=0;y_2=0;y_3=0;

Oh=zeros(H,1);    %Output from NN middle layer
I=Oh;             %Input to NN middle layer
error_2=0;
error_1=0;


ts=0.1;
sys=tf(8.761,[1,4.185,8.761]);  
dsys=c2d(sys,ts,'z');
[num,den]=tfdata(dsys,'v');





for k=1:1:100
time(k)=k*ts;


rin(k)=1.0;
yout(k)=-den(2)*y_1-den(3)*y_2+num(2)*u_1+num(3)*u_2;
  


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

xi=[rin(k),yout(k),error(k),1];

x(1)=error(k)-error_1;
x(2)=error(k);
x(3)=error(k)-2*error_1+error_2;

epid=[x(1);x(2);x(3)];
I=xi*wi';
for j=1:1:H
    Oh(j)=(exp(I(j))-exp(-I(j)))/(exp(I(j))+exp(-I(j))); %Middle Layer
end
K=wo*Oh;             %Output Layer
for l=1:1:Out
    K(l)=exp(K(l))/(exp(K(l))+exp(-K(l)));        %Getting kp,ki,kd
end
kp(k)=K(1);ki(k)=K(2);kd(k)=K(3);
Kpid=[kp(k),ki(k),kd(k)];

du(k)=Kpid*epid;
u(k)=u_1+du(k);

dyu(k)=sign((yout(k)-y_1)/(du(k)-du_1+0.0001));

%Output layer
for j=1:1:Out
    dK(j)=2/(exp(K(j))+exp(-K(j)))^2;
end
for l=1:1:Out
    delta3(l)=error(k)*dyu(k)*epid(l)*dK(l);
end

for l=1:1:Out
   for i=1:1:H
       d_wo=xite*delta3(l)*Oh(i)+alfa*(wo_1-wo_2);
   end
end
    wo=wo_1+d_wo+alfa*(wo_1-wo_2);
%Hidden layer
for i=1:1:H
    dO(i)=4/(exp(I(i))+exp(-I(i)))^2;
end
    segma=delta3*wo;
for i=1:1:H
   delta2(i)=dO(i)*segma(i);
end

d_wi=xite*delta2'*xi;
wi=wi_1+d_wi+alfa*(wi_1-wi_2);

%Parameters Update
du_1=du(k);
u_5=u_4;u_4=u_3;u_3=u_2;u_2=u_1;u_1=u(k);   
y_2=y_1;y_1=yout(k);
   
wo_3=wo_2;
wo_2=wo_1;
wo_1=wo;
   
wi_3=wi_2;
wi_2=wi_1;
wi_1=wi;

error_2=error_1;
error_1=error(k);
end
kp(end)
ki(end)
kd(end)
figure(1);
plot(time,rin,'r',time,yout,'b');
xlabel('time(s)');ylabel('rin,yout');
grid on 
figure(2);
plot(time,error,'r');
xlabel('time(s)');ylabel('error');
grid on 
figure(3);
plot(time,u,'r');
xlabel('time(s)');ylabel('u');
grid on 
figure(4);
subplot(311);
plot(time,kp,'r');
xlabel('time(s)');ylabel('kp');
grid on 
subplot(312);
plot(time,ki,'g');
xlabel('time(s)');ylabel('ki');
grid on 
subplot(313);
plot(time,kd,'b');
xlabel('time(s)');ylabel('kd');
grid on