Modelling & Simulatio Of Engineering System

Question 1

Combien de type de modelisation et quoi ?

Answer 1

Continue M&S
Discrete M&S
Multi-body M&S

Question 2

Process modelling VS simulation

Answer 2

Physical system —> Modelling —> mathematical model—> Model Compilation—> Simulation program—> Trajectory behavior

Question 3

Les differents types d’équation

Answer 3

Differential equations contain time derivatives such as dx/dt, usually denoted 𝑥̇

𝑥̇=𝑎.𝑥+3

Algebraic equations do not include any differentiated variables

𝑥^2+𝑦^2 =𝐿^2

Partial differential equations contain derivatives with respect to other variables than time

𝜕𝑎/𝜕𝑡=(𝜕^2 𝑎)/(𝜕𝑧^2 )

Difference equations express relations between variables, for example at different points in time

𝑥(𝑡+1)=3𝑥(𝑡)+2

Question 4

Diff entre continuous time et discrete time

Answer 4

Continuous-Time (A): A dynamic model whose variable values evolve continuously over time. It is represented by differential equations with time derivatives of some model variables.

Discrete-Time (B): A dynamic model whose variable values evolve only at discrete points in time. It is represented by sets of difference equations, or as computer programs mapping the state of the model at one point in time to the state at the next point in time.

Question 5

Difference entre Acausal Physical Modelling

et Causal Block-Oriented Modelling

Answer 5

Acausal Physical Modelling:
Close to the real circuit
No signal flow

Causal Block-Oriented Modelling
Physical topology is lost
Signal flows
Different definitions of components (Res1, Res2)

Question 6

Comment modeliser un système electrique ?

Answer 6

loi des noeuds

loi des mailles

Question 7

Qu’est ce que modelica et que sais-tu dessus ?

Answer 7

Language – Modelica is not a software

Multi-domain modelling – Combine electrical, mechanical, thermodynamic, hydraulic…

Object-Oriented – Everything is a class and OO concepts such as inheritance

Visual component programming – Graphical modelling in addition to equation-based modelling

Multi-level modelling - Hierarchical systems architecture

Standardised – The Modelica Association specifies and maintains the language

Non-proprietary – No single owner, many implementations in proprietary (Dymola, Worlfram SystemModeler, LMS…) and non-propriertary (OpenModelica, JModelica,…) tools

Question 8

Comment on peut représenter un systeme sur modelica

Answer 8

de deux manières: représentatio graphique et avec du code:

Question 9

Est ce que le langage modelica est orienté objet ?

Answer 9

oui

Question 10

quel type de modelling est system modeler

Answer 10

a continuous modeler

Question 11

quel type de modelling est stateflow

Answer 11

a discrete modeler

Question 12

que doit on faire pour l’utiliser

Answer 12

1) Define States
- déterminer les différents modes avant de faire la modelisation

2) Define States Hierachy
- Déterminer les différences entre les modes et faire des cubes imbriqués en déterminant les relations hierarchiques entre les nodes

3) Define States Decomposition
The decomposition of a state dictates whether its substates execute exclusively of each other — as exclusive (OR) states — or can be activated at the same time — as parallel (AND) states. No two exclusive (OR) states can ever be active at the same time, while any number of parallel (AND) states

tu dis que Off et ON sont des exclusive (OR) states par exemple (tu def si les états que ta créer sont compatibles ou non)

4) Define State Actions and Variables
At this stage of the workflow for developing Stateflow charts, you must determine if any of your states require local or persistent variables.

la tu dis “mettre FAN1 à 0 quand on appuis sur OFF”

5) Define Transitions
Fan1.off to Fan1.ON when ….
C’est les changement automatiques quoi

6) Define Events
Les événements sont des objets non graphiques qui déclenchent des activités pendant l’exécution d’un diagramme d’état. Selon l’endroit et la manière dont vous définissez les événements, ceux-ci peuvent déclencher une transition, une action à exécuter et un statut d’état à évaluer.

Question 13

Multi-body modelling and simulation can be used for…

x4

Answer 13

Kinematics analysis

Dynamics analysis

Rigid bodies

Deformable / Flexible bodies

Question 14

un ex de logiciel ?

Answer 14

PTC Creo

SystemModeler

Question 15

Avantage DMU (digital mockup)

Answer 15

Eviter les couts de prototypes

assurer la validiter des tests

Question 16

Qu’apporte le DMU

Answer 16

une complete représenation du produit avec différente version durant le développement du produit

• specification
• architecture definition

Question 17

Quel type de simulation permettent les DMU(interconnection)

Answer 17

– FEM methods
– Specification tests
– System behavior analysis
– Production issues
– Natural interaction (Virtual reality)

Question 18

A quoi peut servir le DMU

Answer 18

And can lead to optimization capacity for
– optimal design
– robust design

Question 19

Que permet le DMU en terme de technique ?

Answer 19

●Parametrization of a CAD model (reminder)
● Creation of dimensional product family
● Creation and management of topological
product configurations; Creation and
management of multiple views
● Idealization and simplification tools

Question 20

FBS (Gero) ?

Answer 20

● Gero proposed a cognitive
model for product definition.
● When investigating a product we
always loop over function,
behavior and structure issues.
● Every product information can
be classified under these
vision
● It is a result of experimental
observation of design
discussions

Question 21

B-rep ?

Answer 21

Un objet est représenté par sa surface:

sommets, segments, faces

Question 22

Multiple représentation: a quoi ça sert

Answer 22

C’est le fait de représenterdifféremment le produit pour améliorer certaines features. Par exemple la mechnanical reprsentaitonet la electrical représentation d’un produit

Question 23

Quel est le principal probleme ou but de CAD parametric modelling ?

Answer 23

The main issue is to control the geometric
model to quickly adapt the geometry via a
selection of parameters.