Model Verification in Simulink: What It Is and How It Works

Model verification in Simulink is the process of checking that your simulation model behaves correctly and meets its design requirements. It involves running tests and analyzing results to confirm the model's accuracy before deployment or further development.

How It Works

Model verification in Simulink works like a quality check for your simulation model. Imagine building a toy car and then testing if it moves as expected. Similarly, Simulink lets you run your model with different inputs and checks if the outputs match what you expect.

This process uses test cases, which are sets of inputs and expected outputs, to automatically compare the model's behavior against the requirements. If the model's output matches the expected results, it passes verification; if not, you know where to fix it.

Example

This example shows how to verify a simple Simulink model that adds two numbers using a test harness and assertions.

matlab

model = 'add_two_numbers';
new_system(model);
open_system(model);

add_block('simulink/Sources/Constant', [model '/Constant1'], 'Value', '3');
add_block('simulink/Sources/Constant', [model '/Constant2'], 'Value', '5');
add_block('simulink/Math Operations/Add', [model '/Add']);
add_block('simulink/Sinks/Out1', [model '/Out1']);

add_line(model, 'Constant1/1', 'Add/1');
add_line(model, 'Constant2/1', 'Add/2');
add_line(model, 'Add/1', 'Out1/1');

% Create a test harness
harnessName = [model '_harness'];
harness(model, 'Create', harnessName);

% Add an assertion block to check output equals 8
add_block('simulink/Logic and Bit Operations/Assertion', [harnessName '/Assert']);
set_param([harnessName '/Assert'], 'Assertion', 'y == 8');

% Connect Add output to assertion
add_line(harnessName, 'Add/1', 'Assert/1');

% Simulate the harness
simOut = sim(harnessName);

% Check if assertion passed
assertionFailed = simOut.get(''AssertionFailed'');
if assertionFailed
    disp(''Verification failed: output is not 8'');
else
    disp(''Verification passed: output is 8'');
end

Output

Verification passed: output is 8

When to Use

Use model verification in Simulink whenever you want to ensure your model works correctly before using it in real applications. This is especially important in safety-critical systems like automotive or aerospace, where errors can be costly or dangerous.

Verification helps catch mistakes early, saves time by automating tests, and builds confidence that your model meets its design goals. It is useful during development, after changes, or before handing off the model to others.

Key Points

• Model verification checks if a Simulink model behaves as expected.
• It uses test cases and assertions to compare outputs against requirements.
• Verification helps find errors early and ensures model quality.
• It is essential for safety-critical and complex system models.

Key Takeaways

Model verification confirms your Simulink model meets its design requirements.

It uses tests and assertions to automatically check model outputs.

Verification is crucial before deploying models in real-world systems.

Automated verification saves time and improves model reliability.