Model-based design concept in Simulink - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new Simulink model named 'myModel'.

Simulink

model = [1]('myModel');

Drag options to blanks, or click blank then click option'

Aopen_system

Bsave_system

Cnew_system

Dclose_system

Attempts:

3 left

💡 Hint

Common Mistakes

Using open_system instead of new_system

Using save_system before creating the model

The new_system function creates a new Simulink model with the given name.

2fill in blank

medium

Complete the code to add a Gain block to the model 'myModel'.

Simulink

add_block('simulink/Math Operations/Gain', 'myModel/[1]');

Drag options to blanks, or click blank then click option'

AGain1

BSum1

CScope1

DConstant1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Sum1' which is a different block type

Using 'Scope1' or 'Constant1' which are unrelated blocks

The block name should be descriptive and unique. 'Gain1' is the default name for a Gain block.

3fill in blank

hard

Fix the error in the code to set the Gain block's gain value to 5.

Simulink

set_param('myModel/Gain1', '[1]', '5');

Drag options to blanks, or click blank then click option'

Again

BGain

CGainValue

DGainParam

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'gain' which is incorrect

Using 'GainValue' or 'GainParam' which do not exist

The correct parameter name to set the gain value is 'Gain' with a capital G.

4fill in blank

hard

Fill both blanks to connect the output of 'Gain1' to the input of 'Scope1' in 'myModel'.

Simulink

add_block('simulink/Sinks/Scope', 'myModel/Scope1');
add_line('myModel', [1], [2]);

Drag options to blanks, or click blank then click option'

A'Gain1/1'

B'Scope1/1'

C'Gain1/2'

D'Scope1/2'

Attempts:

3 left

💡 Hint

Common Mistakes

Connecting wrong ports like 'Gain1/2' or 'Scope1/2'

Reversing source and destination ports

The line connects output port 1 of 'Gain1' to input port 1 of 'Scope1'.

5fill in blank

hard

Fill all three blanks to simulate the model 'myModel' and get the simulation output.

Simulink

simOut = sim('[1]');
output = simOut.[2];
disp(output.[3]);

Drag options to blanks, or click blank then click option'

AmyModel

Blogsout

Csignals

Dsimlog

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong model name in sim function

Accessing wrong output properties

We simulate 'myModel', access the logged output 'logsout', and then get the 'signals' data to display.

Practice

1. What is the main idea behind Model-based design in Simulink?

easy

A. Building system models using visual blocks to simulate behavior

B. Writing code line by line to create a system

C. Using spreadsheets to analyze data

D. Manually assembling hardware components

Solution

1. Step 1: Understand model-based design in Simulink

   Model-based design uses visual blocks to create models representing systems. Simulink allows simulation of these models to test system behavior before building real hardware.

2. Final Answer:

   Building system models using visual blocks to simulate behavior -> Option A

3. Quick Check:

   Model-based design = Visual block modeling [OK]

Hint: Think visual blocks, not code or hardware [OK]

Common Mistakes:

• Confusing model-based design with coding
• Thinking it involves hardware assembly
• Assuming it uses spreadsheets

2. Which of the following is the correct way to start a new model in Simulink?

easy

A. Use the command start_simulation()

B. Write new_model() in MATLAB command window

C. Open a text editor and type the model code

D. Click File > New > Model

Solution

1. Step 1: Recall Simulink interface basics

   Simulink models are created via the graphical interface using File > New > Model, not by typing commands.

2. Final Answer:

   Click File > New > Model -> Option D

3. Quick Check:

   New model = File > New > Model [OK]

Hint: Use menus, not commands, to create models [OK]

Common Mistakes:

• Trying to create models by MATLAB commands
• Confusing simulation start with model creation
• Using text editors for Simulink models

3. Given this Simulink model snippet, what will the output be after simulation?

Input Signal: Constant block with value 5
Block: Gain block with gain 3
Output: Connected to Gain block output

medium

A. Output will be 5

B. Output will be 8

C. Output will be 15

D. Simulation will fail due to missing blocks

Solution

1. Step 1: Understand blocks and calculate output

   The Constant block outputs 5. The Gain block multiplies input by 3: 5 * 3 = 15.

2. Final Answer:

   Output will be 15 -> Option C

3. Quick Check:

   5 * 3 = 15 [OK]

Hint: Multiply constant by gain for output [OK]

Common Mistakes:

• Adding instead of multiplying
• Confusing input and output values
• Assuming simulation error without reason

4. You created a Simulink model but the simulation does not run. Which of these is the most likely cause?

medium

A. Simulation time set to zero

B. Using too many blocks

C. Model saved in wrong folder

D. Missing connection between blocks

Solution

1. Step 1: Check common simulation errors

   Simulation won't run if simulation time is zero because no time passes. Missing connections cause errors but usually show warnings; too many blocks or folder location don't stop simulation.

2. Final Answer:

   Simulation time set to zero -> Option A

3. Quick Check:

   Simulation time > 0 needed [OK]

Hint: Check simulation time is not zero [OK]

Common Mistakes:

• Ignoring simulation time settings
• Assuming folder location stops simulation
• Thinking too many blocks cause failure

5. You want to model a system where an input signal is doubled, then 4 is added, and finally the result is squared. Which Simulink block sequence correctly represents this?

hard

A. Sum block (+4) -> Gain block (gain=2) -> Math Function block (square)

B. Gain block (gain=2) -> Sum block (+4) -> Math Function block (square)

C. Math Function block (square) -> Gain block (gain=2) -> Sum block (+4)

D. Gain block (gain=2) -> Math Function block (square) -> Sum block (+4)

Solution

1. Step 1: Analyze required operations order

   Input first doubled (Gain=2), then +4 (Sum), then squared (Math Function). Matches Gain -> Sum -> Math Function.

2. Final Answer:

   Gain block (gain=2) -> Sum block (+4) -> Math Function block (square) -> Option B

3. Quick Check:

   Order matters: multiply, add, then square [OK]

Hint: Follow math order: multiply, add, then square [OK]

Common Mistakes:

• Changing operation order
• Adding before multiplying
• Squaring before adding