How can I implement MISO state space Model in Simulink?

Hello Dear

I have these equations as plant in state space form( x_dot= Ax+Bw*w+Bu*u+Bref*vref and z= Cz*x + Dzw* w+ Dzu*u), so how can I implement this plant in Simulink ? or by codes?

good luck with thanks!

Answer 1

[Simran]

Hi @Mohammed Yakoob,

I see you have an equation as plant in “state space” form, which you want to implement in Simulink or by codes. Here’s how you do this:

In Simulink:

1.) Launch Simulink and create a brand new model.

2.) Drag and drop the State-Space block from the Simulink Library Browser under Continuous.

3.) Now double click the block and in its “parameters dialog”, enter your matrices “A”, “B”, “C”, “D” in the respective slides.

A: Enter the state matrix ().

B: Enter the combined input matrix if you want to handle multiple inputs.

C: Enter the output matrix ().

D: Enter the direct transmission matrix based on your system.

4.) For inputs like u, v and , use “Inports” and for output like z, use “Outport”.

6.) Connect the input ports to the “State-Space block” and the output of the “State-Space block” to the output port.

7.) Lastly run the simulation and observe the system behaviour.

For implementing in MATLAB code, you can use the following code:

% Define matrices 
A = [...]; % Define your A matrix 
Bw = [...]; % Define your Bw matrix 
Bu = [...]; % Define your Bu matrix 
Bref = [...]; % Define your Bref matrix 
Cz = [...]; % Define your Cz matrix 
Dzw = [...]; % Define your Dzw matrix 
Dzu = [...]; % Define your Dzu matrix 

% Combine B matrices for multiple inputs 
B = [Bu, Bw, Bref]; 
D = [Dzu, Dzw, zeros(size(Cz, 1), size(Bref, 2))]; 

% Create state-space model 
sys = ss(A, B, Cz, D); 

% Define input signals 
t = 0:0.01:10; % Time vector 
u = [...]; % Define your input signal for u 
w = [...]; % Define your disturbance signal for w 
vref = [...]; % Define your reference signal for vref 

% Combine inputs into a single matrix 
inputs = [u; w; vref]; 

% Simulate the system 
[y, t, x] = lsim(sys, inputs, t); 

% Plot the output 
plot(t, y); 
xlabel('Time (s)'); 
ylabel('Output z'); 
title('State-Space System Output'); 

I used some example values for input and got this graph:

[Sam Chak]

Hi @Simran

Typical simulations involving state-space models should include the initial values, which can be specified in the State-Space block. Your explanations would have been more meaningful if you had included the Simulink block diagram.