Simulink - User Guide

4090 Pages·2017·38.87 MB·English

®
Simulink
User's Guide
R2017b
How to Contact MathWorks
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®
Simulink User's Guide
© COPYRIGHT 1990–2017 by The MathWorks, Inc.
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Revision History
November 1990 First printing New for Simulink 1
December 1996 Second printing Revised for Simulink 2
January 1999 Third printing Revised for Simulink 3 (Release 11)
November 2000 Fourth printing Revised for Simulink 4 (Release 12)
July 2002 Fifth printing Revised for Simulink 5 (Release 13)
April 2003 Online only Revised for Simulink 5.1 (Release 13SP1)
April 2004 Online only Revised for Simulink 5.1.1 (Release 13SP1+)
June 2004 Sixth printing Revised for Simulink 5.0 (Release 14)
October 2004 Seventh printing Revised for Simulink 6.1 (Release 14SP1)
March 2005 Online only Revised for Simulink 6.2 (Release 14SP2)
September 2005 Eighth printing Revised for Simulink 6.3 (Release 14SP3)
March 2006 Online only Revised for Simulink 6.4 (Release 2006a)
March 2006 Ninth printing Revised for Simulink 6.4 (Release 2006a)
September 2006 Online only Revised for Simulink 6.5 (Release 2006b)
March 2007 Online only Revised for Simulink 6.6 (Release 2007a)
September 2007 Online only Revised for Simulink 7.0 (Release 2007b)
March 2008 Online only Revised for Simulink 7.1 (Release 2008a)
October 2008 Online only Revised for Simulink 7.2 (Release 2008b)
March 2009 Online only Revised for Simulink 7.3 (Release 2009a)
September 2009 Online only Revised for Simulink 7.4 (Release 2009b)
March 2010 Online only Revised for Simulink 7.5 (Release 2010a)
September 2010 Online only Revised for Simulink 7.6 (Release 2010b)
April 2011 Online only Revised for Simulink 7.7 (Release 2011a)
September 2011 Online only Revised for Simulink 7.8 (Release 2011b)
March 2012 Online only Revised for Simulink 7.9 (Release 2012a)
September 2012 Online only Revised for Simulink 8.0 (Release 2012b)
March 2013 Online only Revised for Simulink 8.1 (Release 2013a)
September 2013 Online only Revised for Simulink 8.2 (Release 2013b)
March 2014 Online only Revised for Simulink 8.3 (Release 2014a)
October 2014 Online only Revised for Simulink 8.4 (Release 2014b)
March 2015 Online only Revised for Simulink 8.5 (Release 2015a)
September 2015 Online only Revised for Simulink 8.6 (Release 2015b)
October 2015 Online only Rereleased for Simulink 8.5.1 (Release
2015aSP1)
March 2016 Online only Revised for Simulink 8.7 (Release 2016a)
September 2016 Online only Revised for Simulink 8.8 (Release 2016b)
March 2017 Online only Revised for Simulink 8.9 (Release 2017a)
September 2017 Online only Revised for Simulink 9.0 (Release 2017b)
Contents
Introduction to Simulink
Simulink Basics
1
Start the Simulink Software . . . . . . . . . . . . . . . . . . . . . . . 1-2
Start the MATLAB Software . . . . . . . . . . . . . . . . . . . . . 1-2
Open the Simulink Editor . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Open the Library Browser . . . . . . . . . . . . . . . . . . . . . . . 1-3
Create and Open Models . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Create a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Use Customized Settings When Creating New Models . . 1-8
Open a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Load Variables When Opening a Model . . . . . . . . . . . . 1-10
Open a Model with Different Character Encoding . . . . . 1-11
Simulink Model File Types . . . . . . . . . . . . . . . . . . . . . . 1-11
Programmatic Modeling Basics . . . . . . . . . . . . . . . . . . . . 1-13
Load a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Create a Model and Specify Parameter Settings . . . . . . 1-13
Programmatically Load Variables When Opening a
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Programmatically Add and Connect Blocks . . . . . . . . . . 1-15
Name a Signal Programmatically . . . . . . . . . . . . . . . . . 1-17
Open the Same Model in Multiple Windows . . . . . . . . . 1-17
Get a Simulink Identifier . . . . . . . . . . . . . . . . . . . . . . . 1-18
Specify Colors Programmatically . . . . . . . . . . . . . . . . . 1-21
Build and Edit a Model in the Simulink Editor . . . . . . . 1-23
Start Simulink and Create a Model . . . . . . . . . . . . . . . . 1-23
Add Blocks to the Model . . . . . . . . . . . . . . . . . . . . . . . . 1-23
Align and Connect Blocks . . . . . . . . . . . . . . . . . . . . . . . 1-24
v
Set Block Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
Add More Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
Branch a Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
Organize Your Model . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Simulate Model and View Results . . . . . . . . . . . . . . . . . 1-31
Modify the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
Save a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
How to Tell If a Model Needs Saving . . . . . . . . . . . . . . . 1-37
Save a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
What Happens When You Save a Model? . . . . . . . . . . . 1-38
Save Models in the SLX File Format . . . . . . . . . . . . . . . 1-39
Save Models with Different Character Encodings . . . . . 1-41
Export a Model to a Previous Simulink Version . . . . . . 1-43
Save from One Earlier Simulink Version to Another . . . 1-44
Model Editing Environment . . . . . . . . . . . . . . . . . . . . . . 1-45
Simulink Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-45
Interactive Model Building . . . . . . . . . . . . . . . . . . . . . . 1-47
Model Design Error Detection . . . . . . . . . . . . . . . . . . . . 1-48
Library Browser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-48
Setting Properties and Parameters . . . . . . . . . . . . . . . . 1-50
Parts of a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
About Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
Block Parameters and Properties in Simulink . . . . . . . . 1-54
Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-56
Preview Content of Hierarchical Items . . . . . . . . . . . . . 1-58
What Is Content Preview? . . . . . . . . . . . . . . . . . . . . . . 1-58
Enable Content Preview . . . . . . . . . . . . . . . . . . . . . . . . 1-59
What Content Preview Displays . . . . . . . . . . . . . . . . . . 1-59
Use Viewmarks to Save Views of Models . . . . . . . . . . . . 1-61
What Are Viewmarks? . . . . . . . . . . . . . . . . . . . . . . . . . 1-61
Create a Viewmark . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-62
Open and Navigate Viewmarks . . . . . . . . . . . . . . . . . . . 1-63
Manage Viewmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-63
Refresh a Viewmark . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-64
Update Diagram and Run Simulation . . . . . . . . . . . . . . 1-65
Updating the Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 1-65
Simulation Updates the Diagram . . . . . . . . . . . . . . . . . 1-65
vi Contents
Update Diagram While Editing . . . . . . . . . . . . . . . . . . . 1-65
Simulate a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-66
Print Model Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-68
Print Interactively or Programmatically . . . . . . . . . . . . 1-68
Printing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-68
Canvas Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-68
Basic Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-70
Print the vdp Model Using Default Settings . . . . . . . . . 1-70
Print a Subsystem Hierarchy . . . . . . . . . . . . . . . . . . . . 1-72
Select the Systems to Print . . . . . . . . . . . . . . . . . . . . . . . 1-74
Print Current System . . . . . . . . . . . . . . . . . . . . . . . . . . 1-74
Print Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-74
Print a Model Referencing Hierarchy . . . . . . . . . . . . . . 1-75
Specify the Page Layout and Print Job . . . . . . . . . . . . . 1-77
Page and Print Job Setup . . . . . . . . . . . . . . . . . . . . . . . 1-77
Set Paper Size and Orientation Without Printing . . . . . 1-77
Tiled Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-78
Print Multiple Pages for Large Models . . . . . . . . . . . . . . 1-79
Add a Log of Printed Models . . . . . . . . . . . . . . . . . . . . . . 1-80
Add a Sample Time Legend . . . . . . . . . . . . . . . . . . . . . . . 1-81
Print from the MATLAB Command Line . . . . . . . . . . . . 1-82
Printing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82
Print Systems with Multiline Names or Names with
Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82
Set Paper Orientation and Type . . . . . . . . . . . . . . . . . . 1-83
Position and Size a System . . . . . . . . . . . . . . . . . . . . . . 1-83
Use Tiled Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-84
Print to a PDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-86
Print Model Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
Model Report Options . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
vii
Print Models to Image File Formats . . . . . . . . . . . . . . . . 1-90
Copy Model Views to Third-Party Applications . . . . . . . 1-90
Keyboard and Mouse Actions for Simulink Modeling . . 1-91
Object Selection and Clipboard Operations . . . . . . . . . . 1-91
Block and Signal Line Shortcuts and Actions . . . . . . . . 1-92
Signal Name and Label Actions . . . . . . . . . . . . . . . . . . 1-93
Simulation Keyboard Shortcuts . . . . . . . . . . . . . . . . . . 1-94
Debugging and Breakpoints Keyboard Shortcuts . . . . . 1-94
Zooming and Scrolling Shortcuts . . . . . . . . . . . . . . . . . . 1-94
Library Browser Shortcuts . . . . . . . . . . . . . . . . . . . . . . 1-95
File Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-96
Simulation Stepping
2
How Simulation Stepper Helps With Model Analysis . . . 2-2
How Stepping Through a Simulation Works . . . . . . . . . . 2-3
Simulation Snapshots . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
How Simulation Stepper Uses Snapshots . . . . . . . . . . . . 2-4
How Simulation Stepper Differs from Simulink
Debugger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Use Simulation Stepper . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Simulation Stepper Access . . . . . . . . . . . . . . . . . . . . . . . 2-8
Simulation Stepper Pause Status . . . . . . . . . . . . . . . . . . 2-8
Tune Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Referenced Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Simulation Stepper and Interval Logging . . . . . . . . . . . 2-10
Simulation Stepper and Stateflow Debugger . . . . . . . . . 2-10
Simulation Stepper Limitations . . . . . . . . . . . . . . . . . . . 2-12
Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Model Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Step Through a Simulation . . . . . . . . . . . . . . . . . . . . . . . 2-15
Step Forward and Back . . . . . . . . . . . . . . . . . . . . . . . . 2-15
viii Contents
Set Conditional Breakpoints for Stepping a
Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
Add and Edit Conditional Breakpoints . . . . . . . . . . . . . 2-18
Observe Conditional Breakpoint Values . . . . . . . . . . . . 2-19
How Simulink Works
3
How Simulink Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Modeling Dynamic Systems . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Block Diagram Semantics . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Creating Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Block Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Tunable Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Block Sample Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Custom Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Systems and Subsystems . . . . . . . . . . . . . . . . . . . . . . . 3-10
Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
Block Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Model Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Simulation Phases in Dynamic Systems . . . . . . . . . . . . . 3-17
Model Compilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Link Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Simulation Loop Phase . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Solvers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Fixed-Step Solvers Versus Variable-Step Solvers . . . . . 3-21
Continuous Versus Discrete Solvers . . . . . . . . . . . . . . . 3-21
Minor Time Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Shape Preservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Zero-Crossing Detection . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
Demonstrating Effects of Excessive Zero-Crossing
Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
How the Simulator Can Miss Zero-Crossing Events . . . 3-29
Preventing Excessive Zero Crossings . . . . . . . . . . . . . . 3-29
ix
Zero-Crossing Algorithms . . . . . . . . . . . . . . . . . . . . . . . 3-31
Understanding Signal Threshold . . . . . . . . . . . . . . . . . 3-32
How Blocks Work with Zero-Crossing Detection . . . . . . 3-33
Algebraic Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
What Is an Algebraic Loop? . . . . . . . . . . . . . . . . . . . . . 3-37
Interpretations of Algebraic Loops . . . . . . . . . . . . . . . . 3-38
What is an Artificial Algebraic Loop? . . . . . . . . . . . . . . 3-41
Why Algebraic Loops Are Undesirable . . . . . . . . . . . . . 3-42
Identify Algebraic Loops in Your Model . . . . . . . . . . . . 3-43
How to Handle Algebraic Loops in a Model . . . . . . . . . . 3-46
How the Algebraic Loop Solver Works . . . . . . . . . . . . . 3-48
Remove Algebraic Loops . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Remove Artificial Algebraic Loops . . . . . . . . . . . . . . . . . 3-53
How Simulink Eliminates Artificial Algebraic Loops . . . 3-64
When Simulink Cannot Eliminate Artificial Algebraic
Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-70
Managing Large Models with Artificial Algebraic
Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-72
Model Blocks and Direct Feedthrough . . . . . . . . . . . . . 3-73
Changing Block Priorities When Using Algebraic Loop
Solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-74
Modeling Dynamic Systems
Creating a Model
4
Create a Template from a Model . . . . . . . . . . . . . . . . . . . . 4-2
Describe Models Using Annotations . . . . . . . . . . . . . . . . . 4-3
Add a Text Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Resize an Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Make an Annotation Interactive . . . . . . . . . . . . . . . . . . . 4-4
Add an Image Annotation . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Use TeX Commands in an Annotation . . . . . . . . . . . . . . 4-5
Add Lines to Connect Annotations to Blocks . . . . . . . . . . 4-6
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