Set simulation time and fixed step size for a Simulink model from the command line

Hi! I have a simulink model that I need to simulate over a few different durations and with a fixed (but different) sampling time. So what I want to do is to set this from the command line without having to start up simulink and change it manually each time.

To clarify I want to set the simulation duration (or the start time/stop time) and the solver options to Fixed-step (or at least change the step-size). So it would look something like this in a script/the command line:

 sim('simModel', 'simulationTime', [0 10], 'solverOptions.stepSize', 1/1024)

Where 'simModel' is the simulink model in question.

It doesn't have to look like this, but just to give you an idea of what I want to do. Is there a way to do this?

I can't really find it in the documentations, the only thing I find is how to set the sampling time for a specific block, but I want to keep those as inherited.

Answer 1

[Sebastian Castro]

If you open the model's Configuration Parameters, for each parameter you can right-click and select "What's This?". This will open up some documentation, which includes a table that shows you how to programmatically use that parameter.

So, you can take that and use it in the sim command as you specified:

>> sim('modelName','StartTime','0','StopTime','10','FixedStep','0.2');

Notice that the properties have to take a string value and not a numeric value. This is where the num2str function comes in handy. For example,

for Ts = 0.01:0.01:0.1
  simout = sim('modelName','FixedStep',num2str(Ts));
end

- Sebastian

[Tomas Nilsson]

Thank you, I did not know that you could right click an element like that, it is very handy. Thank you.

[RHYTHM GOYAL]

Thank You so much sir. It is of great help and made things much easier. Thank You.

[Rik]

Flagged by Chrisitan Wolter 10 minutes ago.

It's Importend and very usefull. Also it's my first Flag, and i will see, if I can find it easiler with that

That is not what flags are for. A guide to flag or close questions.

[mehdi azari]

I want to change the simulation time from seconds to minutes and hours. How should I do this?

[Walter Roberson]

@mehdi azari

The stop time always have to be passed to simulink in seconds; https://www.mathworks.com/help/simulink/gui/stop-time.html

If you have hours and minutes then

st_secs = seconds( hours(NumberOfHours) + minutes(NumberOfMinutes) );
num2str(st_secs)

or

st_secs = seconds( duration(NumberofHours, NumberOfMinutes, 0) )
num2str(st_secs)