How can I measure length of signal in simulink?

39 ビュー (過去 30 日間)
George Francis
George Francis 2018 年 3 月 17 日
コメント済み: Jim Riggs 2018 年 3 月 19 日
Hello guys, I have model with "matlab function block" in which I have recursive least square method. Recursive algorithm needs to know length of incoming signal in order to work correctly. But when I use command N=length(y) it returns me length N= 1. But I think it should give me higher length.
Matlab function block code "rls_iden6"
function [P,N] = fcn(u,y)
N = length(y);
sigma=1;
C = sigma*eye(2); %p
P = ones(2,1);
z= [y; u];
lamda=1;
for n=1:N
sample_out = y(n);
C = (C - ( (C*z*z'*C)/( lamda+(z'*C*z) ) ))/lamda;
P = P + (C*z* (sample_out - (z'*P)));
end
My final code should look like it's shown below, because it works in matlab workspace. Simulink should give me 5 parameters instead of just 2.
load data_cela.mat
u=U; %input
y=Y; %output
input = 3;
output = 2;
system = input + output;
N = length(y);
%initial conditions
sigma = 1;
C = sigma*eye(system);
P = ones(system,1);
lamda = 1; %forgetting factor
for n=3:N
for i=1:2
W(i) = y(n-i); %output
end
for i=1:3
V(i) = u(n-i+1); %input
end
z = [V';W'];
sample_out = y(n);
pom(n)= z' * P;
error(n) = y(n) - pom(n);
C = (C - ( (C*z*z'*C)/( lamda+(z'*C*z) ) ))/lamda;
P = P + (C*z* (sample_out - (z'*P) ) );
change(1:system,n) = P;
end
f_param = [P(1:3);-P(4:5)];
num = [P(1:3,1)];
den = [1;-P(4:5,1)];
num1 = num(3,1);
trasferfunction = tf(num1,den',1)
Result:
0.002879
----------------------
z^2 - 1.883 z + 0.8873
  1 件のコメント
Jim Riggs
Jim Riggs 2018 年 3 月 19 日
Verify the signal size in Simulink. In the Simulink window, select Display / Signals & Ports / Signal Dimensions.
This will show the signal size (according to Simulink) in your model.

サインインしてコメントする。

回答 (0 件)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by