Running a simulation in Simulink - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start the Simulink simulation.

Simulink

sim('[1]')

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

AsimulinkModel

BstartSim

CrunSim

DmodelName

Attempts:

3 left

💡 Hint

Common Mistakes

Using function names like 'startSim' instead of the model name.

Not putting the model name in quotes.

The sim function runs the Simulink model specified by its name as a string.

2fill in blank

medium

Complete the code to set the simulation stop time to 10 seconds.

Simulink

set_param('[1]', 'StopTime', '[2]')

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

AmodelName

B10

CstartTime

DstopTime

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names instead of strings.

Setting stop time as a number instead of a string.

The set_param function sets parameters for the Simulink model. 'StopTime' is set to '10' seconds as a string.

3fill in blank

hard

Fix the error in the code to run the simulation and get the output.

Simulink

out = sim('[1]');

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

AmodelName

Bsimulink

Cmodel

DrunModel

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names that do not match the model name.

Omitting quotes around the model name.

The sim function requires the exact model name as a string to run the simulation and return output.

4fill in blank

hard

Fill both blanks to set the solver type to 'ode45'.

Simulink

set_param('[1]', 'Solver', '[2]')

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

AmodelName

Bode45

Cnormal

Daccelerator

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing solver type with simulation mode.

Using incorrect strings for solver.

The set_param function sets the solver type to 'ode45' for the model specified by its name.

5fill in blank

hard

Fill all three blanks to run the simulation, get the output, and plot the signal named 'yout'.

Simulink

out = sim('[1]');
plot(out.[2].time, out.[3].signals.values);

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

AmodelName

Byout

DsimOut

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names for output signals.

Not accessing the time and values correctly.

This code runs the simulation of the model, then plots the time and signal values of 'yout' from the output.

Practice

1. What is the main purpose of running a simulation in Simulink?

easy

A. To test and analyze a model's behavior without building physical hardware

B. To write code faster

C. To create graphical user interfaces

D. To compile the model into an executable file

Solution

1. Step 1: Understand simulation purpose

   Simulation allows testing how a model behaves in a virtual environment.

2. Step 2: Compare options

   Only To test and analyze a model's behavior without building physical hardware describes testing and analyzing without physical hardware.

3. Final Answer:

   To test and analyze a model's behavior without building physical hardware -> Option A

4. Quick Check:

   Simulation = safe model testing [OK]

Hint: Simulation means testing model behavior virtually [OK]

Common Mistakes:

• Confusing simulation with code writing
• Thinking simulation creates GUIs
• Assuming simulation compiles code

2. Which command correctly starts a simulation of a Simulink model named myModel?

easy

A. sim('myModel')

B. execute('myModel')

C. start_sim('myModel')

D. run('myModel')

Solution

1. Step 1: Recall Simulink simulation command

   The correct command to run a simulation is sim('modelName').

2. Step 2: Match command to options

   Only sim('myModel') uses sim('myModel') correctly.

3. Final Answer:

   sim('myModel') -> Option A

4. Quick Check:

   sim command runs simulation [OK]

Hint: Use sim('modelName') to start simulation [OK]

Common Mistakes:

• Using run() instead of sim()
• Trying start_sim() which is invalid
• Using execute() which is not a Simulink command

3. Given the code:

out = sim('simpleModel', 'StopTime', '10');
disp(out.tout(end));

What will be displayed?

medium

A. 0

B. 10

C. Simulation error

D. Undefined variable

Solution

1. Step 1: Understand sim command with StopTime

   The simulation runs from time 0 to 10 seconds.

2. Step 2: Check output time vector

   out.tout stores simulation time points; end is last time point, which is 10.

3. Final Answer:

   10 -> Option B

4. Quick Check:

   Simulation end time = 10 [OK]

Hint: tout(end) shows simulation stop time [OK]

Common Mistakes:

• Assuming output is 0 instead of final time
• Expecting an error without cause
• Confusing variable names

4. What is wrong with this code snippet to run a simulation?

sim('modelName', StopTime=20);

medium

A. The StopTime parameter is misspelled

B. The model name must be a variable, not a string

C. StopTime should be a string, not a variable

D. sim command cannot take parameters

Solution

1. Step 1: Check parameter syntax for sim

   Parameters like StopTime must be passed as strings: 'StopTime', '20'.

2. Step 2: Identify error in code

   Code uses StopTime=20 without quotes, causing syntax error.

3. Final Answer:

   StopTime should be a string, not a variable -> Option C

4. Quick Check:

   Parameter names and values must be strings [OK]

Hint: Use quotes for parameter names and values [OK]

Common Mistakes:

• Passing parameters without quotes
• Confusing variable and string types
• Thinking sim can't take parameters

5. You want to run a simulation of controlModel from 0 to 15 seconds and save the output to variable simOut. Which code correctly does this and allows you to access the simulation output data?

hard

A. sim('controlModel', 'StopTime', 15, 'Output', simOut);

B. sim('controlModel', 'StartTime', '0', 'EndTime', '15');

C. simOut = run('controlModel', StopTime='15');

D. simOut = sim('controlModel', 'StopTime', '15');

Solution

1. Step 1: Identify correct sim syntax for stop time and output

   Use sim('modelName', 'StopTime', 'time') and assign output to a variable.

2. Step 2: Evaluate options

   simOut = sim('controlModel', 'StopTime', '15'); correctly assigns output to simOut and sets stop time as string '15'. Others have syntax errors or wrong commands.

3. Final Answer:

   simOut = sim('controlModel', 'StopTime', '15'); -> Option D

4. Quick Check:

   Assign sim output to variable with sim('model', 'StopTime', 'time') [OK]

Hint: Assign sim output to variable; use 'StopTime' as string [OK]

Common Mistakes:

• Passing StopTime as number without quotes
• Using run() instead of sim()
• Incorrect parameter names like StartTime/EndTime