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BP神经网络整定的PID控制算法matlab源程序,系统为二阶闭环系统。 ! O* `4 D% ^: S$ v+ [7 H& f
%BP based PID Control clear all; close all;
+ ^+ d# S& Y% Ixite=0.28; alfa=0.001; 3 v) m1 R% @+ @$ |- I. o; H' \
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IN=4;H=5;Out=3; %NN Structure
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wi=0.50*rands(H,IN); wi_1=wi;wi_2=wi;wi_3=wi;
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) f5 q! b2 Y, h: z# vwo=0.50*rands(Out,H); wo_1=wo;wo_2=wo;wo_3=wo; 1 ]% I. Z4 L; H( ]# r
- e W/ J2 z. s1 {0 j& m) ~x=[0,0,0]; u_1=0;u_2=0;u_3=0;u_4=0;u_5=0; y_1=0;y_2=0;y_3=0;
) y% s3 m. t7 ]2 m# N3 O& uOh=zeros(H,1); %Output from NN middle layer I=Oh; %Input to NN middle layer error_2=0; error_1=0;
" f$ i- ?' d, w3 I+ Pts=0.01; sys=tf(2.6126,[1,3.201,2.7225]); %建立被控对象传递函数 dsys=c2d(sys,ts,'z'); %把传递函数离散化 [num,den]=tfdata(dsys,'v'); %离散化后提取分子、分母 for k=1:1:2000 time(k)=k*ts; rin(k)=40; yout(k)=-den(2)*y_1-den(3)*y_2+num(2)*u_2+num(3)*u_3;%这一步是怎么推的(问题1) error(k)=rin(k)-yout(k); 1 r8 A2 y T( N" o
xi=[rin(k),yout(k),error(k),1];
. o$ K* s) h: l1 Ox(1)=error(k)-error_1; x(2)=error(k); x(3)=error(k)-2*error_1+error_2;
5 B* R! l; T4 i1 w tepid=[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)]; . l! a/ p I H& p! o/ [
du(k)=Kpid*epid; u(k)=u_1+du(k); if u(k)>=45 % Restricting the output of controller u(k)=45; end if u(k)<=-45 u(k)=-45; end ( c4 w; I" d' K2 y; A- K
dyu(k)=sign((yout(k)-y_1)/(u(k)-u_1+0.0000001)); % v% O- @ Q3 @
%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
0 T& ~8 W; e F: u* ifor 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);%这一步似乎有问题(问题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 . `6 T9 t8 v9 _% Y" H9 O! i6 j
d_wi=xite*delta2'*xi; wi=wi_1+d_wi+alfa*(wi_1-wi_2); 2 B" m) z/ V/ h4 O
%Parameters Update 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; 3 h) A+ C1 q- E+ a
error_2=error_1; error_1=error(k); end figure(1); plot(time,rin,'r',time,yout,'b'); xlabel('time(s)');ylabel('rin,yout'); figure(2); plot(time,error,'r'); xlabel('time(s)');ylabel('error'); figure(3); plot(time,u,'r'); xlabel('time(s)');ylabel('u'); figure(4); subplot(311); plot(time,kp,'r'); xlabel('time(s)');ylabel('kp'); subplot(312); plot(time,ki,'g'); xlabel('time(s)');ylabel('ki'); subplot(313); plot(time,kd,'b'); xlabel('time(s)');ylabel('kd'); 问题(1)和问题(2)都标注出来了。还请各位帮忙看一下,尤其是问题(1),到底如何将已知的传递函数转换成,matlab的仿真模型呢 ; J+ i& F3 C. C7 I- l
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