Model-based development workflow in Simulink - Mini Project: Build & Apply

Model-based development workflow

📖 Scenario: You are working on a simple control system for a home heating system. You want to create a model that takes the current temperature and decides whether to turn the heater on or off.

🎯 Goal: Build a basic Simulink model that implements a simple control logic: if the temperature is below a threshold, the heater turns on; otherwise, it stays off.

📋 What You'll Learn

Create a Simulink model with input and output blocks

Add a threshold configuration variable

Implement the control logic using Simulink blocks

Display the output signal showing heater status

💡 Why This Matters

🌍 Real World

Model-based development is used in engineering to design and test control systems before building physical devices.

💼 Career

Understanding model-based workflows is important for roles in control engineering, embedded systems, and simulation-based testing.

1

Create the initial Simulink model with input and output

Create a Simulink model named HeatingControl. Add an input block named TemperatureInput and an output block named HeaterOutput.

Simulink

% Create a new Simulink model named HeatingControl
% Add an input block named TemperatureInput
% Add an output block named HeaterOutput
% Your code here

Hint

Use new_system to create the model and add_block to add input and output blocks.

2

Add a threshold configuration variable

In the MATLAB workspace, create a variable named temperatureThreshold and set it to 20. This will be the temperature below which the heater turns on.

Simulink

% Create a new Simulink model named HeatingControl
new_system('HeatingControl')
open_system('HeatingControl')
add_block('simulink/Sources/In1','HeatingControl/TemperatureInput')
add_block('simulink/Sinks/Out1','HeatingControl/HeaterOutput')

% Create the threshold variable
% Your code here

Hint

Simply assign the value 20 to the variable temperatureThreshold in the workspace.

3

Implement the control logic using Simulink blocks

In the HeatingControl model, add a Constant block with value temperatureThreshold. Add a Relational Operator block set to <. Connect TemperatureInput and the Constant block to the Relational Operator. Connect the output of the Relational Operator to HeaterOutput.

Simulink

% Create a new Simulink model named HeatingControl
new_system('HeatingControl')
open_system('HeatingControl')
add_block('simulink/Sources/In1','HeatingControl/TemperatureInput')
add_block('simulink/Sinks/Out1','HeatingControl/HeaterOutput')

% Create the threshold variable
temperatureThreshold = 20;

% Add Constant and Relational Operator blocks and connect them
% Your code here

Hint

Use add_block to add the Constant and Relational Operator blocks. Use set_param to set their parameters. Use add_line to connect the blocks.

4

Display the output signal showing heater status

Run the simulation for 10 seconds with the input temperature set to 18. Use sim to run the model and logsout or Scope to display the heater output signal.

Simulink

% Create a new Simulink model named HeatingControl
new_system('HeatingControl')
open_system('HeatingControl')
add_block('simulink/Sources/In1','HeatingControl/TemperatureInput')
add_block('simulink/Sinks/Out1','HeatingControl/HeaterOutput')

% Create the threshold variable
temperatureThreshold = 20;

% Add Constant block with value temperatureThreshold
add_block('simulink/Sources/Constant','HeatingControl/ThresholdConstant')
set_param('HeatingControl/ThresholdConstant','Value','temperatureThreshold')

% Add Relational Operator block set to less than
add_block('simulink/Logic and Bit Operations/Relational Operator','HeatingControl/RelOp')
set_param('HeatingControl/RelOp','Operator','<')

% Connect blocks
add_line('HeatingControl','TemperatureInput/1','RelOp/1')
add_line('HeatingControl','ThresholdConstant/1','RelOp/2')
add_line('HeatingControl','RelOp/1','HeaterOutput/1')

% Set input temperature to 18 and run simulation for 10 seconds
% Your code here

Hint

Use set_param to set the input value, sim to run the model, and disp to show the output.

Practice

1. What is the main purpose of using a model-based development workflow in Simulink?

easy

A. To replace hardware testing completely

B. To design and test systems visually before coding

C. To only generate reports from data

D. To write code manually without simulation

Solution

1. Step 1: Understand model-based development

   Model-based development uses visual blocks to create system models.

2. Step 2: Identify the workflow goal

   The goal is to design and test systems visually before writing code.

3. Final Answer:

   To design and test systems visually before coding -> Option B

4. Quick Check:

   Model-based development = Visual design and testing [OK]

Hint: Model-based means design visually, not just code [OK]

Common Mistakes:

• Thinking it only generates reports
• Assuming no simulation is involved
• Believing it replaces all hardware testing

2. Which of the following is the correct first step in a Simulink model-based development workflow?

easy

A. Generate code automatically

B. Deploy the model to hardware

C. Create a visual model using blocks

D. Write manual test scripts

Solution

1. Step 1: Identify the workflow sequence

   The first step is to create a visual model using blocks in Simulink.

2. Step 2: Understand next steps

   Code generation and deployment come after modeling and testing.

3. Final Answer:

   Create a visual model using blocks -> Option C

4. Quick Check:

   First step = Build model [OK]

Hint: Start by building the model visually [OK]

Common Mistakes:

• Trying to generate code before modeling
• Deploying before testing
• Writing manual scripts instead of modeling

3. Given the following Simulink workflow steps: 1) Create model, 2) Simulate model, 3) Generate code, 4) Deploy code. What is the output after step 2?

medium

A. Error logs from deployment

B. Executable code for hardware

C. Visual blocks for model creation

D. Simulation results showing system behavior

Solution

1. Step 1: Identify step 2 in the workflow

   Step 2 is to simulate the model, which runs the system virtually.

2. Step 2: Determine simulation output

   Simulation produces results showing how the system behaves.

3. Final Answer:

   Simulation results showing system behavior -> Option D

4. Quick Check:

   Simulation output = Behavior results [OK]

Hint: Simulation shows system behavior, not code [OK]

Common Mistakes:

• Confusing simulation with code generation
• Expecting executable code after simulation
• Thinking deployment errors appear before deployment

4. You created a Simulink model and tried to generate code, but got an error saying 'Model contains unresolved references'. What should you do to fix this?

medium

A. Check and resolve all block references and dependencies

B. Ignore the error and deploy the model

C. Delete the model and start over

D. Skip simulation and generate code again

Solution

1. Step 1: Understand the error meaning

   'Unresolved references' means some blocks or data sources are missing or not linked.

2. Step 2: Fix the references

   Check all blocks and dependencies to ensure they are correctly connected and available.

3. Final Answer:

   Check and resolve all block references and dependencies -> Option A

4. Quick Check:

   Fix references before code generation [OK]

Hint: Resolve all missing links before code generation [OK]

Common Mistakes:

• Ignoring errors and proceeding
• Deleting model unnecessarily
• Skipping simulation thinking it fixes errors

5. You want to speed up your development by automatically generating code from your Simulink model and deploying it to hardware. Which sequence correctly represents the model-based development workflow?

hard

A. Create model -> Simulate model -> Generate code -> Deploy code

B. Simulate model -> Create model -> Generate code -> Deploy code

C. Create model -> Generate code -> Simulate model -> Deploy code

D. Generate code -> Create model -> Simulate model -> Deploy code

Solution

1. Step 1: Identify correct workflow order

   The correct order starts with creating the model, then simulating it to test behavior.

2. Step 2: Follow with code generation and deployment

   After successful simulation, generate code and deploy to hardware.

3. Final Answer:

   Create model -> Simulate model -> Generate code -> Deploy code -> Option A

4. Quick Check:

   Workflow order = Model, simulate, code, deploy [OK]

Hint: Model first, simulate second, then code and deploy [OK]

Common Mistakes:

• Generating code before simulation
• Deploying before code generation
• Simulating after code generation