MATLAB: Error while executing the simulation

anti-resonancelsimsstranspose

clear all

close all

clc

s = -14.5

A = [-3, 5, -7, 0; 0.5, -1.5, 0.5, -7.5; -5, 0, -3, 0; -0.5, -5, 0, -7];

B = [1, 0; 0, -1; -2, 0; 0, 1];

C = [1, 0, 0, 0; 0, -1, 0, 0];

D = [-1, 0; 2, 0];

sys = ss(A,B,C,D);

M = (s*eye(4,4) – A);

P = [ M, -B; C, D]

k = rank(P)

uM = null(P,'r')

I = transpose(uM)

%sys2 = tf( sys );

t = linspace(0, 2.5, 10).';

x_zero = transpose([0,0,0,-0.1333])

u = x_zero.*exp(-14.5*t)

x0= initial(sys,x_zero)

[y,t] = lsim(sys ,u , t)

error that I am receiving:-

Matrix dimensions must agree.

Error in antiresonance_part_two (line 36)

u = x_zero.*-exp(-14.5*t)

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See my Answer to your duplicate Question how to simulate using lsim command I am receiving error because of variable 't'(time). It took a few minutes to find out what the problem was and then propose a solution.

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MATLAB: How to simulate using lsim command I am receiving error because of variable ‘t'(time).

The input ‘u’ must have the same number of columns as ‘B’.

I have no idea what you actually want to do (or what your ‘u’ is), so in their absence, try this as a relevant (and working) example with your system:

A = [-3, 5, -7, 0; 0.5, -1.5, 0.5, -7.5; -5, 0, -3, 0; -0.5, -5, 0, -7];
B = [1, 0; 0, -1; -2, 0; 0, 1];
C = [1, 0, 0, 0; 0, -1, 0, 0];
D = [-1, 0; 2, 0];
sys = ss(A,B,C,D);
t = linspace(0, 2.5, 250).';
u = sin(2*pi*t*[1 5]);
[y,t] = lsim(sys, u, t);
figure
yyaxis left
plot(t, u(:,1), '--b')
hold on
plot(t, u(:,2), '--r')
hold off
yyaxis right
plot(t, y(:,1), '-b')
hold on
plot(t, y(:,2), '-r')
hold off
grid
xlabel('Time')
ylabel('Amplitude')
legend('u_1', 'u_2', 'y_1', 'y_2', 'Location','N')

Make appropriate changes to get the result you want.

MATLAB: I want to use ‘u’ as zero matrix in order to simulate the matrix but I am receiving the following error, which is mentioned below the code. what’s the possible solution

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.

Let us look at what you have

t = 0:0.1:10;
size(t)
ans = 1×2
     1   101

t has 101 samples. According to the error message (which we will assume to be correct as it says the same thing as the documentation for lsim says), as many rows as samples in the time u must have 101 rows as well.

u = zeros([4 1]) %this is the matrix because of which I am receiving error

That is clearly 1 column. Does it satisfy as many columns as input channels ?

C = [1, 0, 0, 0; 0, -1, 0, 0];

2 rows for C -> two input channels. So u must have two columns because the system has two input channels.

Therefore, you would be able to get something to run if you used

u = zeros(length(y), 2);

Would it be a meaningful run? Probably not. Row K of u should be the list of inputs corresponding to time t(K), so using zeros() like that is telling lsim() that the inputs are zero at every time step. Not impossible, but not likely.

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Related Solutions

MATLAB: How to simulate using lsim command I am receiving error because of variable ‘t'(time).

MATLAB: I want to use ‘u’ as zero matrix in order to simulate the matrix but I am receiving the following error, which is mentioned below the code. what’s the possible solution

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