Modelica and Virtual EducationModelica Conference 2019, Regensburg, Germany

Christian Kral

2019-03-05

(C) Christian Kral, 2019-03-02 — 1

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 2

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 3

Online Quiz

Go to https://kahoot.it/

Create your own quiz at https://kahoot.com/

Online Quiz

Go to https://kahoot.it/

Create your own quiz at https://kahoot.com/

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 6

Modelica BookGo to https://kahoot.it/

Theory and practiceModelica for electricalengineersPolyphase electrical machinesIncluding GitHub tutorialLink to Hanser (publisher)Link to video tutorialOpen Source▶ Software OpenModelica▶ Examples and models

Look into the bookat the booth of LTX

(C) Christian Kral, 2019-03-02 — 7

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 8

Introduction

Education of engineersTheory classesExercises in class or homeworkLaboratorySimulation (e.g., with Modelica)

(C) Christian Kral, 2019-03-02 — 9

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 10

Letto

Letto meansLearningEvaluatingTeachingTestingOnline

LettoWebpage and Wiki at https://www.letto.at/Commercial softwareRunning on Linux server

(C) Christian Kral, 2019-03-02 — 11

Letto Key Performance Indicators

Customized for technical studiesText, data and calculations in one databaseFull support of Maxima(open source computer algebra system)Supports quantities = numbers and unitsSymbolic calculationsReal and complex number calculationsManagement of students classes and subjectsSupport of syllabus competencesOnline exercises, exams and grading▶ Student may access actual contributions and grades▶ Compliant with General Data Protection Regulation

(C) Christian Kral, 2019-03-02 — 12

Letto Key Performance Indicators

Individual Data ExamplesSpecified data range of parametersReal and complex number calculationsPowerful plugins▶ DC circuit generator▶ AC circuit generator▶ Analog meter▶ Digital graphs (RS 232, UART, etc.)▶ Graph (Maxima)▶ Freehand sketch▶ Source code (Java, Java script, C)

(C) Christian Kral, 2019-03-02 — 13

Letto Key Performance Indicators

Types of examplesMultiple choice questionsMultiple answer calculations▶ Calculation accuracy▶ Multiple »correct« answers▶ Handle subsequent errors

Mapping questions and answersGap text exercisesFree text fields

(C) Christian Kral, 2019-03-02 — 14

Letto Multiple Choice ExampleOhm’s law

(C) Christian Kral, 2019-03-02 — 15

Letto Multiple Answer ExampleOhm’s law

(C) Christian Kral, 2019-03-02 — 16

Letto Meter ReadingOhm’s law

(C) Christian Kral, 2019-03-02 — 17

Letto Matching Question and AnswerComplex AC series circuit

(C) Christian Kral, 2019-03-02 — 18

Letto + Modelica Example

ExampleInvestigation of R-C seriescircuitIndividual exercise dataComplex supply voltageV = V∠phiV

Resistance R

Capacitance CFrequency f

I

V

R

C

DeterminePhase angle ofimpedance phi

Active power PReactive power QApparent power S

(C) Christian Kral, 2019-03-02 — 19

Letto + Modelica Example

ExampleInvestigation of R-C seriescircuitIndividual exercise dataComplex supply voltageV = V∠phiV

Resistance R

Capacitance CFrequency f

I

V

R

C

DeterminePhase angle ofimpedance phi

Active power PReactive power QApparent power S

(C) Christian Kral, 2019-03-02 — 20

Letto + Modelica Example

The starting pointLecturer

Specification of task by PDF documentIndividual exercise data stored in CSV fileProvided through Moodle

(C) Christian Kral, 2019-03-02 — 21

Letto + Modelica Example

The starting pointStudents

Download assignmentFill in individual resultsUpload CSV file on Moodle

(C) Christian Kral, 2019-03-02 — 22

Letto + Modelica Example

The starting pointEvaluation by lecturer

Download all students resultsCompile all results into one student results fileCreate reference data (Modelica ▷ KeyWordIO)

(C) Christian Kral, 2019-03-02 — 23

Letto + Modelica Example

The starting pointGrading by lecturer

Grading script (Python / Julia)Compare student results with reference dataProvide grading scheme▶ Achievable points per question▶ Accuracy

Degradation scheme▶ Wrong sign▶ Wrong magnitude of order▶ Accuracy exceeded▶ Subsequent error

Grading

(C) Christian Kral, 2019-03-02 — 24

Letto + Modelica Example

The much better solutionImport data into LettoKeep together▶ Exercise text▶ Data▶ Result tolerances▶ Grading scheme

Post processing of data by MaximaApply in one example▶ Multiple calculation▶ Multiple choice▶ Matching questions and answers

Letto + Modelica Example

Letto screenshot

(C) Christian Kral, 2019-03-02 — 26

Letto + Modelica Example

Categories ▷ teaching subjects ▷ semesters

(C) Christian Kral, 2019-03-02 — 27

Letto + Modelica Example

Test administration ▷ class ▷ subject ▷ test type

(C) Christian Kral, 2019-03-02 — 28

Letto + Modelica Example

Examples assigned to categories

(C) Christian Kral, 2019-03-02 — 29

Letto + Modelica ExampleExample details ▷ editor ▷ LATEXsupport ▷ variables ▷ units ▷digits ▷ display format ▷ plugin graphics ▷ input fields

(C) Christian Kral, 2019-03-02 — 30

Letto + Modelica Example

Create plugin ▷ assign maximum points ▷ unit penalty

(C) Christian Kral, 2019-03-02 — 31

Letto + Modelica Example

Define or import data sets

(C) Christian Kral, 2019-03-02 — 32

Letto + Modelica ExampleAnswer details ▷ Maxima result ▷ target unit ▷ resultaccuracy ▷ question type ▷ hints

(C) Christian Kral, 2019-03-02 — 33

Letto + Modelica Example

Maxima code ▷ post processing

(C) Christian Kral, 2019-03-02 — 34

Letto + Modelica ExamplePreview | Student mode

(C) Christian Kral, 2019-03-02 — 35

Letto Grading

Exercise results

Letto Grading

Individual exercise results

(C) Christian Kral, 2019-03-02 — 37

Letto GradingIndividual exercise results

(C) Christian Kral, 2019-03-02 — 38

Letto

LearningConsider different learning styles▶ Individual▶ Group▶ Sharing

Repetitive exercisesEvaluationGrading

(C) Christian Kral, 2019-03-02 — 39

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 40

Virtual Modelica Lab

Virtual lab objectivesDemonstration of practical applicationsDeepening of theoretical knowledgePreparation studies prior to lab exerciseCompensation exercise in case of lab absence

Work performed by Michael Obermeier @ OTH RegensburgSupervised by Prof. Anton Haumer

(C) Christian Kral, 2019-03-02 — 41

Virtual Modelica Lab

Lab setup

(C) Christian Kral, 2019-03-02 — 42

Virtual Modelica LabMachine characteristics

0 500 1000 1500-10

0

10

20

30

40

50

60

torq

ue [N

⋅ m]

speed [rpm]

Y connection D connection load

(C) Christian Kral, 2019-03-02 — 43

Virtual Modelica LabTool chain

Modelica toolLabviewMoBA Simulator (TLK-Thermo GmbH)

(C) Christian Kral, 2019-03-02 — 44

Virtual Modelica Lab

Functional mockup unit (FMU)

S

High priority

synchronizeRealtime

imc wtau

load

J=JLoad

torqueLoad

limiter

uMax=+1

~grid

400/50

globalSeedstart

yd

load

(C) Christian Kral, 2019-03-02 — 45

Virtual Modelica Lab

Key Performance IndicatorsModelica_DeviceDrivers ∼ realtimeAdd measuring noiseLabview▶ control buttons▶ scope graphs

(C) Christian Kral, 2019-03-02 — 46

Virtual Modelica Lab

OutlookDevelopment of additional▶ input▶ output

interfacesStandalone application (license)Web access to National Instruments Virtual Instrument

(C) Christian Kral, 2019-03-02 — 47

Table of Contents

1 Online Quiz

2 Modelica Book

3 Introduction

4 Letto and Modelica

5 Virtual Modelica Lab

6 Conclusions

(C) Christian Kral, 2019-03-02 — 48

Conclusions

Online Kahoot quizModelica BookIntroduction to Letto▶ Features▶ Selected examples▶ Grading

Virtual Modelica Lab▶ Objectives plus implementation▶ Live demonstration

(C) Christian Kral, 2019-03-02 — 49

(C) Christian Kral, 2019-03-02 — 50