MATLAB Answers

0

Lsim with two input signal

Asked by Francesco Marruccelli on 6 Feb 2018
Latest activity Answered by Aveek Podder on 22 Feb 2018
I have this system
A = [ 1 1 -1 ; 0 -1 1 ; 0 1 -1 ];
B = [ 1 0 ; 0 1 ; 0 0 ];
C = [ 1 0 0 ];
D = [ 0 ] ;
sys = ss( A , B , C , D )
Now i have to put two signals in input with lsim the two signals are u1( t ) = 2*square( t ) and u2( t ) = 0 i have written something like this
figure( 2 ) ;
t = 0:0.01:10 ;
u = [ 2*square( t ) ];
u2 = zeros( size( t ) ) ;
sys2 = tf( sys ) ;
lsim( sys2 , u , t , x0 );
but i continue to have this error
Error using DynamicSystem/lsim (line 97) When simulating the response to a specific input signal, the input data U must be a matrix with as many rows as samples in the time vector T, and as many columns as input channels.
I have tried many ways but i don't know what to do it there isn't nothing on the internet on multi input with lsim please help !
I thank in advance any of you

  0 Comments

Sign in to comment.

1 Answer

Answer by Aveek Podder on 22 Feb 2018

Hi,
The input matrix B defined is a 3x2 Matrix, by doing this we have defined a two-input system. For lsim to function as expected we need to pass both the inputs. The error message says the same.
To resolve the issue pass both the input, please use the following command:
>> lsim( sys2 , [u;u2] , t , x0 );
For more information on lsim please have a look at the following link:

  0 Comments

Sign in to comment.