智能控制(神经网络)-作业

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智能控制作业

学生： 学 号： 专业班级：

7-2 采用BP网路、RBF网路、DRNN网路逼近线性对象

u(k?1)?0.9?y(k?1)y(k)?，分别进行matlab仿真。 21?y(k?1)（一）采用BP网络仿真

网络结构为2-6-1。采样时间1ms，输入信号u(k)?0.5sin(6??t)，权值W1,W2的初值随机取值，??0.05,??0.05。

仿真m文件程序为： %BP simulation clear all; clear all;

xite=0.5; alfa=0.5;

w1=rands(2,6); % value of w1,initially by random w1_1=w1;w1_2=w1;

w2=rands(6,1); % value of w2,initially by random w2_1=w2;w2_2=w2_1;

dw1=0*w1;

x=[0,0]';

u_1=0; y_1=0;

I=[0,0,0,0,0,0]'; % input of yinhanceng cell Iout=[0,0,0,0,0,0]'; % output of yinhanceng cell FI=[0,0,0,0,0,0]';

ts=0.001;

for k=1:1:1000

time(k)=k*ts;

u(k)=0.5*sin(3*2*pi*k*ts);

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y(k)=(u_1-0.9*y_1)/(1+y_1^2);

for j=1:1:6

I(j)=x'*w1(:,j);

Iout(j)=1/(1+exp(-I(j))); end

yn(k)=w2'*Iout; %output of network e(k)=y(k)-yn(k); % error calculation

w2=w2_1+(xite*e(k))*Iout+alfa*(w2_1-w2_2); % rectify of w2

for j=1:1:6

FI(j)=exp(-I(j))/(1+exp(-I(j))^2); end

for i=1:1:2 for j=1:1:6

dw1(i,j)=e(k)*xite*FI(j)*w2(j)*x(i); % dw1 calculation end end

w1=w1_1+dw1+alfa*(w1_1-w1_2); % rectify of w1

% jacobian information yu=0;

for j=1:1:6

yu=yu+w2(j)*w1(1,j)*FI(j); end

dyu(k)=yu;

x(1)=u(k); x(2)=y(k);

w1_2=w1_1;w1_1=w1; w2_2=w2_1;w2_1=w2; u_1=u(k); y_1=y(k); end

figure(1);

plot(time,y,'r',time,yn,'b');

xlabel('times');ylabel('y and yn'); figure(2);

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plot(time,y-yn,'r');

xlabel('times');ylabel('error'); figure(3);

plot(time,dyu);

xlabel('times');ylabel('dyu');

运行结果为：

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