FFRLS方法的等效电路模型参数辨识matlab代码
时间: 2024-04-19 18:08:02 浏览: 8
FFRLS方法是一种递归最小二乘法,用于参数辨识。其等效电路模型参数辨识的Matlab代码如下:
```matlab
% FFRLS algorithm for equivalent circuit modeling parameter identification
clear all;
close all;
clc;
% Generate the input and output signals
t = 0:0.01:10;
u = sin(t);
y = 0.5*exp(-t).*sin(3*t);
% Define the equivalent circuit model
R1 = 1;
C1 = 1;
R2 = 0.5;
C2 = 0.5;
% Calculate the number of parameters
n = length([R1,C1,R2,C2]);
% Define the initial values of the parameters
theta = [1.5,1.5,0.5,0.5]';
% Define the forgetting factor and the regularization parameter
lambda = 0.99;
delta = 0.01;
% Initialize the variables
P = eye(n)/delta;
e = zeros(length(t),1);
theta_rec = zeros(n,length(t));
% Perform the FFRLS algorithm
for i = 1:length(t)
phi = [exp(-t(i)/R1), t(i)/C1, exp(-t(i)/R2), t(i)/C2];
yhat = phi'*theta;
e(i) = y(i) - yhat;
k = (lambda*P*phi)/(1+lambda*phi'*P*phi);
theta = theta + k*e(i);
P = (P - lambda*k*phi'*P)/lambda;
theta_rec(:,i) = theta;
end
% Plot the results
subplot(2,1,1)
plot(t,y,'b',t,phi'*theta_rec,'r')
legend('Actual','Model')
ylabel('y')
xlabel('t')
subplot(2,1,2)
plot(t,theta_rec(1,:),'b',t,theta_rec(2,:),'r',t,theta_rec(3,:),'g',t,theta_rec(4,:),'y')
legend('R1','C1','R2','C2')
ylabel('Parameter value')
xlabel('t')
```
该代码中,我们首先生成了输入输出信号,然后定义了等效电路模型的参数,并计算了参数数量n。接下来,我们定义了初始参数值theta,以及遗忘因子lambda和正则化参数delta。然后,我们初始化了变量P、e和theta_rec,并通过循环执行FFRLS算法,更新参数theta、P和e,并将theta的值存储在theta_rec中。最后,我们绘制了模型输出和参数随时间的变化曲线。