Simulink: changing parameter mid-simulation

Hi all,

I am trying to run a Simulink model with 12 "In" blocks and 4 "out" blocks" using a Matlab script.

One of those 12 inputs is a variable called "input_boucle" which is initially set at value 0.

I would like the simulation to last 5 seconds and at time = 3 seconds, I want the "input_boucle" variable to switch from 0 to 1 for the remaining of the simulation.

My initial script was quite simple:

t_stop = 5;
T_s = t_stop/1000;

options = simset('SrcWorkspace','current', 'fixedstep', T_s) ;

sim('test_all_InOut_Blocks.slx',t_stop, options);

I would like to have something like this:

save_mat_file_InOut_blocks; % That's where I create my workspace with all the variables

t_stop_ouverte = 5;
T_s = t_stop_ouverte/1000;

options_boucle_ouverte = simset('SrcWorkspace','current', 'fixedstep', T_s) ;

sim('test_all_InOut_Blocks.slx',t_stop_ouverte, options_boucle_ouverte)

set_param('test_all_InOut_Blocks','SimulationCommand','pause') % But how do I specify to stop at 3 seconds?
input_Boucle.signals.values = double(0); % 1: boucle ouverte, 0: boucle fermée
set_param('test_all_InOut_Blocks','SimulationCommand','continue') 

I understand that this is the way:

With the assertion having for command:

set_param(bdroot,'SimulationCommand','pause'),
disp(sprintf('\nSimulation paused.'))

As advised here: https://fr.mathworks.com/help/simulink/ug/controlling-execution-of-a-simulation.html

But how can I integrate my inital model to this model?

Would anyone know how to solve my issue?

Thanks in advance!

Answer 1

[Jon]

I would just run one simulation for 5 seconds and put in a switch as shown in the first example below. Note you could probably make it even a little simpler using the second example below, but this only works because the two values you switch between happen to be 0 and 1 which correspond to logical false, true. The first approach would allow switching between any two values

[Nafalai]

This looks great, thanks a lot! How do you call the block which allows me to regroup my initial model right after the assertation one please? I'll try your method right away

[Jon]

I'm not familiar with the assertion block. Unless I'm missing something, that is not really needed here. Just run for the whole 5 seconds and have the input switch its value using blocks.

Actually now that I have thought about it a little more there is even a simpler way, just using a step source block.

[Jon]

Like this:

[Nafalai]

Thank you for all your help!

[Jon]

Hope you are able to move ahiead with that. If that answered your question please accept the answer. That way other people with a similar problem will know there may be a solution for them too.