How to Run Simulink Models from MATLAB Script Easily

You can run a Simulink model from a MATLAB script using the sim('modelName') command, where modelName is the name of your Simulink model file without the extension. This command starts the simulation and returns simulation results that you can use for further analysis.

Syntax

The basic syntax to run a Simulink model from a MATLAB script is:

• sim('modelName'): Runs the Simulink model named modelName.
• simOut = sim('modelName'): Runs the model and stores simulation output in simOut.
• sim('modelName', 'StopTime', '10'): Runs the model and sets the stop time to 10 seconds.

Replace modelName with your actual Simulink model file name without the .slx extension.

matlab

sim('modelName')
simOut = sim('modelName')
sim('modelName', 'StopTime', '10')

Example

This example shows how to run a Simulink model named simple_model from a MATLAB script and get the simulation output.

matlab

model = 'simple_model';
load_system(model); % Load the model into memory
simOut = sim(model, 'StopTime', '5'); % Run simulation for 5 seconds

% Access simulation output (assuming model has output logged as 'yout')
y = simOut.get('yout');

% Display first few values of output
disp(y(1:5,:));

close_system(model, 0); % Close model without saving

Output

[0.0000 0.0000]
0.5000 0.1000
0.9800 0.1960
1.4400 0.2880
1.8700 0.3740

Common Pitfalls

• Model not loaded: Forgetting to load the model with load_system can cause errors.
• Wrong model name: Using the file name with extension or a wrong name will fail.
• Output not logged: If the model does not log output signals, simOut.get will return empty.
• Simulation parameters: Not setting parameters like StopTime may run the model indefinitely or with default settings.

matlab

%% Wrong way: Using file name with extension
sim('simple_model.slx') % This causes error

%% Right way: Use model name without extension
sim('simple_model')

Quick Reference

Here is a quick summary of commands to run Simulink models from MATLAB scripts:

Command	Description
sim('modelName')	Run the Simulink model named 'modelName'
simOut = sim('modelName')	Run model and save output to variable
sim('modelName', 'StopTime', '10')	Run model with stop time set to 10 seconds
load_system('modelName')	Load model into memory without opening GUI
close_system('modelName', 0)	Close model without saving changes

Key Takeaways

Use sim('modelName') to run a Simulink model from a MATLAB script.

Always use the model name without the .slx extension in the sim command.

Load the model with load_system before simulating for better control.

Set simulation parameters like StopTime to control simulation duration.

Access simulation results from the output object returned by sim.