OpenModelica/C3/Block-Component-Modeling/English - Revision history

Kaushik Datta at 09:53, 15 January 2018

2018-01-15T09:53:57Z

Kaushik Datta at 05:19, 11 April 2016

2016-04-11T05:19:10Z

Kaushik Datta at 05:17, 11 April 2016

2016-04-11T05:17:28Z

Kaushik Datta at 05:10, 11 April 2016

2016-04-11T05:10:28Z

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Kaushik Datta: Created page with "{| border=1 ||'''Visual Cue''' ||'''Narration''' |- || Slide: '''Title Slide''' || Welcome to the spoken tutorial on '''Block component modeling'''. |- || Slide: Learning..."

2016-04-05T05:25:09Z

Created page with "{| border=1 ||'''Visual Cue''' ||'''Narration''' |- || Slide: '''Title Slide''' || Welcome to the spoken tutorial on '''Block component modeling'''. |- || Slide: Learning..."

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{| border=1
||'''Visual Cue'''
||'''Narration'''

|-
|| Slide:

'''Title Slide'''
|| Welcome to the spoken tutorial on '''Block component modeling'''.

|-
|| Slide:

Learning Objectives
|| In this tutorial, you are going to learn:

How to define a '''block'''.

How to connect blocks.

How to use blocks from '''Modelica Standard Library'''.

|-
|| Slide:

System Requirements
|| To record this tutorial, I am using:

* '''OpenModelica 1.9.2'''
* '''Ubuntu''' Operating System version '''14.04'''
* But, this process is identical in '''Windows, Mac OS X''' or '''FOSSEE OS''' on '''ARM'''.

|-
|| Slide:

Prerequisites
|| To understand and practice this tutorial, you need

* Knowledge of class definition in '''Modelica'''.
* Knowledge of '''component oriented modeling''' in '''Modelica'''.
* Prerequisite tutorials are mentioned on our website

|-
|| Slide:

'''block'''
|| '''block''' is a specialized class in '''Modelica'''.
* It is useful in control applications.
* For example, '''Modelica Library''' has blocks for '''PI''' and '''PID''' controllers which are frequently seen in chemical engineering applications.
* variables in a block class must have fixed causality: either input or output.
* '''blocks''' can be connected using '''connect''' statements.

|-
|| Slide:

'''block connectors'''
|| '''block connectors''' are used to model input and output signals.

For example, this is a declaration for '''block connector''' that models '''real''' input.

|-
|| Slide:

'''Problem Statement'''
|| Now, let us try to understand '''block component modeling''' through an example.

Let us write a class that uses blocks to perform the following two operations:

* Take two time varying signals as input and returning their sum as output.
* Take a time varying signal and amplifying it by a constant.

Let us define this problem in detail using schematics.

|-
|| Slide:

Sum of signals
|| The figure shows a schematic for block that takes two signals as input and returns their sum.

To make things simpler, let us choose signal '''1''' to be '''t''' which represents time.

Let signal '''2''' be '''2 (times) t (squared)'''

|-
|| Slide:

'''Amplification of signal'''
|| This is schematic for amplification of signal.

It is similar to the previous case with two inputs and one output.

Let us choose one input to be our signal.

Let the other input be a constant '''K''' by which to amplify the signal.

The product of these two inputs is the output required.

We have chosen the signal '''2''' i.e. '''K''' to be '''5''' units.

|-
|| Slide:

'''MISO'''
|| Notice that both Sum of signals and amplification require a block with '''2''' inputs and '''1''' output.

'''Modelica library''' has a block named '''MISO''' that stands for '''Multiple Input Single Output'''.

It is available in '''Modelica.Interfaces.Blocks''' package.

The input to this block '''u''' is a vector since it can accept multiple signals as input.

'''y''' is the output which is a '''scalar'''.

|-
|| Slide:

'''Solution Methodology'''
|| Let us now discuss how to solve our problem using '''OMEdit'''.

Extend '''MISO''' to create a block named '''Sum'''.

We have learnt about extending a class in previous tutorials.

Extend '''MISO''' to create a block named '''Product'''.

Create a class named '''main'''.

Create instances of '''Sum''' and '''Product''' blocks in the '''main''' class.

Lastly, program the necessary equations related to input and output variables.

Note that '''Sum''' block corresponds to the Sum of signals and '''Product''' to amplification.

|-
||
|| I have already created the necessary blocks and packaged them into a file named '''arithmeticOperationsUsingBlocks'''.

You may locate this file on our website and download it.

|-
||
|| Let me switch to '''OMEdit'''.

I shall first demonstrate the package '''arithmeticOperationsUsingBlocks''' and then demonstrate the syntax of '''MISO''' block.

|-
|| /* Libraries Browser */
|| I have already opened this package in '''OMEdit'''.

Let me expand it in the '''Libraries Browser'''.

Note that the package has blocks named '''Sum''' and '''Product''' and a '''main''' class.

|-
||
|| Double-click on all three of them.

Let me also open '''MISO''' block from '''Modelica Library'''.

|-
||
|| Expand '''Modelica library'''.

Go to '''Blocks → Interfaces'''.

Scroll down a bit.

Double Click on '''MISO Interfaces''' package also has several other blocks which are similar to '''MISO''' in functionality.

|-
||
|| Let me shift '''OMEdit''' window to the left for better visibility.

Let us first look into '''Sum''' block.

|-
|| /* arithmeticOperationsUsingBlocks.Sum */
|| Switch to '''Text View''' if it opens in either '''Icon or Diagram View'''.

|-
|| /* block Sum */
|| This is the syntax for declaring a '''block'''.

|-
|| /* extends Modelica…. */
|| This statement is used to inherit '''MISO block''' from its location in '''Modelica library'''.

We have learnt about '''Class inheritance''' or '''Class extension''' in previous tutorials.

|-
||
|| Let me take a step back for a moment and demonstrate '''MISO block'''.

Go to '''MISO tab'''.

Switch to vText View.'''

|-
|| partial block MISO;
|| '''MISO''' is a partial block which means that it can only be inherited but not instantiated.

|-
|| /* MISO */

// extends Modelica.Blocks.Icons.Block; //
|| '''MISO''' inherits '''Block class'''.

You may locate this in '''Modelica library''' using the path shown.

This class is used here only for the sake of its '''Diagram View''' and hence need not be discussed.

|-
|| /* MISO */

// parameter Integer nin=1 "Number of inputs"; //
|| '''nin''' represents the number of inputs.

This parameter may be changed when the block is inherited.

|-
|| /* MISO */

'''RealInput u[nin];'''
|| '''RealInput''' is a connector which evidently represents a '''real''' input signal.

In this case, the input is a vector '''u''' as we already discussed.

|-
|| /* MISO */

'''RealOutput y;'''
|| Similarly, '''RealOutput''' is a connector which represents a '''real''' output signal.

Here, '''y''' is the real-valued output signal.

|-
||
|| '''RealInput''' and '''RealOutput''' are present in the same package of '''Modelica Library''' as '''MISO'''.

Please look into them.

|-
|| /* MISO Diagram View */
|| Now, let me show you how the '''Diagram View''' of '''MISO block''' looks like.

|-
||
|| Let us go back to '''Sum''' block and continue from where we left off.

|-
|| /* Sum */

// y = Sum(u) //
|| Variables '''y''' and '''u''' are a part of this block since it inherits MISO.

As we have learnt in previous tutorials, '''Sum''' is an '''array''' function.

It takes an '''array''' as input and returns the sum of its elements.

|-
||
|| Now, let me show you the '''Diagram View''' of '''Sum''' block.

|-
|| /* Diagram View of Sum */
|| This Diagram looks like that of '''MISO'''.

This is because '''Sum''' is an inherited class of '''MISO'''.

|-
||
|| Let me now switch to '''Product''' block.

|-
|| /* Product */

// extends …. //
|| This block extends '''MISO''' as well.

|-
|| y = Product(u)
|| As we have seen in previous tutorials, '''Product''' is an array function that takes an array as input.

It returns the product of elements.

|-
||
|| Let me now switch to main class.

Switch to '''Text View'''.

|-
|| /* main */

Sum ..;

Product ..;
|| This indicates instantiation of '''Sum''' and '''Product''' blocks.

These instance can also be created using the drag and drop functionality of '''OMEdit'''.

We discussed this feature in previous tutorials.

|-
|| // nin = 2 //
|| '''nin''' is the parameter for number of input vectors in '''MISO'''.

We assign a value of '''2''' to this parameter.

|-
|| // mySum.u = {time, 2*time} //
|| This equation indicates the values of '''signal 1''' and '''signal 2''' for '''Sum''' of signals which we discussed in slides

|-
|| // myProduct.u = {..} //
|| Similarly, this indicates the values of '''Signal 1''' and '''Signal 2''' for amplification of signal as we already discussed.

|-
||
|| Let me simulate this class.

Click on '''Simulate'''.

|-
|| /* Variables Browser */
|| Expand '''mySum'''.

Click on '''y'''.

This generates a plot that is in accordance with the values provided.

|-
||
|| This brings us to the end of this tutorial.

Let me switch to slides.

|-
|| Slide:

Assignment
|| As an assignment, look into the codes for '''RealInput, RealOutput, SI, SO''' and '''MO''' blocks.

You can find them in '''Modelica.Blocks.Interfaces''' package.

|-
|| Slide:

About the '''Spoken Tutorial project'''
|| Watch the video available at the link shown below

http://spoken-tutorial.org/What\_is\_a\_Spoken\_Tutorial

|-
|| Slide:

'''Spoken Tutorial Workshops'''
|| We conducts workshops using '''spoken tutorials'''.

Give certificates.

Please contact us.

|-
|| Slide:

Forum to answer questions
|| If you have questions in this tutorial, please visit the webpage mentioned.

|-
|| Slide:

'''Textbook Companion Project'''
|| We coordinate coding of solved examples from popular books.

We give honorarium to contributors.

Please visit our website.

|-
|| Slide:

'''Lab Migration Project'''
|| We help migrate labs from commercial simulators to '''OpenModelica'''.

|-
|| Slide:

'''Acknowledgements'''
|| '''Spoken Tutorial Project''' is supported by '''NMEICT, MHRD''', Government of India.

|-
|| Slide:

'''Thanks'''
|| We thank '''OpenModelica''' development team for their support.

|-
||
|| I would like to thank you the listener for joining me in this tutorial.

@@ Line 17: / Line 17: @@
 How to define a '''block'''.
-How to connect ''''blocks'''.
+How to connect '''blocks'''.
 How to use blocks from '''Modelica Library'''.
@@ Line 47: / Line 47: @@
 || Let us now learn more about '''blocks'''.
-'''block''' is a specialized class in '''Modelica'''.
+*'''block''' is a specialized class in '''Modelica'''.
-−
 * It is useful in control applications.
 * For example, '''Modelica Library''' has blocks for '''PI''' and '''PID''' controllers which are frequently seen in chemical engineering control applications.
@@ Line 62: / Line 61: @@
 They are used to model '''input''' and '''output''' signals.
 For example, this is declaration for a '''block connector''' that models '''real''' input signals.

@@ Line 12: / Line 12: @@
 || Slide:
-Learning Objectives
+'''Learning Objectives'''
 || In this tutorial, we are going to learn:
 How to define a '''block'''.
@@ Line 25: / Line 24: @@
 || Slide:
-System Requirements
+'''System Requirements'''
 || To record this tutorial, I am using:
@@ Line 35: / Line 34: @@
 || Slide:
-Prerequisites
+'''Prerequisites'''
 || To understand and practice this tutorial, you need
@@ Line 60: / Line 59: @@
 '''block connectors'''
-|| Connectors acts as interface between blocks.
+|| '''Connectors''' acts as interface between '''blocks'''.
-They are used to model input and output signals.
+They are used to model '''input''' and '''output''' signals.
@@ Line 75: / Line 74: @@
 Let us write a class that uses blocks to perform the following operations:
-* Take two time varying signals as input and output their sum.
+* Take two time varying signals as '''input''' and '''output''' their sum.
 * Take a time varying signal as input and amplify it by a constant.
@@ Line 83: / Line 82: @@
 || Slide:
-Sum of signals
+'''Sum of signals'''
 || This figure shows a schematic for block that takes two signals as input and returns their sum.
@@ Line 94: / Line 93: @@
 '''Amplification of signal'''
-|| This is schematic for amplification of a signal.
+|| This is schematic for amplification of a '''signal'''.
-It is similar to the previous case with two inputs and one output.
+It is similar to the previous case with two '''inputs''' and one '''output'''.
-Let us choose one input to be our signal.
+Let us choose one '''input''' to be our '''signal'''.
-Let the other input i.e. signal 2 be a constant '''K''' by which to amplify the signal.
+Let the other '''input''' i.e. '''signal 2''' be a constant '''K''' by which to amplify the signal.
-The product of these two inputs is the output required.
+The product of these two '''inputs''' is the '''output''' required.
-We have chosen the signal '''2''' i.e. '''K''' to be '''5''' units.
+We have chosen the '''signal 2''' i.e. '''K''' to be '''5''' units.
 |-
@@ Line 136: / Line 135: @@
 Create instances of '''Sum''' and '''Product''' blocks in the '''main''' class.
-Lastly, program the necessary equations related to input and output variables.
+Lastly, program the necessary equations related to '''input''' and '''output''' variables.
-Note that '''Sum''' corresponds to the Sum of signals whereas '''Product''' corresponds to the amplification of signal.
+Note that '''Sum''' corresponds to the Sum of signals whereas '''Product''' corresponds to the '''amplification of signal'''.
 |-
 ||
-|| I have already created the necessary blocks and packaged them into a file named '''arithmeticOperationsUsingBlocks'''.
+|| I have already created the necessary '''blocks '''and packaged them into a file named '''arithmeticOperationsUsingBlocks'''.
 You may locate this file on our website and download it.
@@ Line 262: / Line 261: @@
 // y = Sum(u) //
-|| Variables '''y''' and '''u''' are a part of this block since it inherits MISO.
+|| Variables '''y''' and '''u''' are a part of this block since it inherits '''MISO'''.
 As we have learnt in previous tutorials, '''Sum''' is an '''array''' function.
@@ Line 282: / Line 281: @@
 |-
 || y = Product(u)
-|| As we have seen in previous tutorials, '''Product''' is an array function that takes an array as input.
+|| As we have seen in previous tutorials, '''Product''' is an array function that takes an array as '''input'''.
 It returns the product of its elements.
@@ Line 288: / Line 287: @@
 |-
 ||
-|| Let me now switch to main class.
+|| Let me now switch to '''main''' class.
 Switch to '''Text View'''.
@@ Line 306: / Line 305: @@
 |-
 || // nin = 2 //
-|| '''nin''' is a parameter for dimension of input vector '''u''' in '''MISO'''.
+|| '''nin''' is a parameter for dimension of '''input''' vector '''u''' in '''MISO'''.
 We assign a value of '''2''' to this parameter.
@@ Line 373: / Line 372: @@
 || Slide:
-Forum to answer questions
+'''Forum to answer questions'''
 || If you have questions in this spoken tutorial, please visit the webpage mentioned.

@@ Line 339: / Line 339: @@
 Assignment
-|| As an assignment, look into the codes for '''RealInput, RealOutput, SI, SO''' and '''MO''' blocks.
+|| As an assignment, look into the codes for '''RealInput, RealOutput, SI, SO''' and '''MIMO''' blocks.
 You can find them in '''Modelica.Blocks.Interfaces''' package.