4. Coupling real and virtual assets

Question 1

CouplingMethodologies: Identification&estimation of states&parameters

How can we ensure that our virtual asset remains consistent with the physical asset? and how to find these parameters/inputs for the virtual asset?

Answer 1

For this we need the Inverse Problems and data assimilation: we find the parameters and the **states **from the real assets.
Parameters
* Some parameters are just known (e.g. from the geometric design)
‘Constitutive’ vs. ‘Geometric’ parameters
States
* Dynamics states (e.g. deformations in a component)
* Condition states

Question 2

CouplingMethodologies: Identification&estimation of states&parameters

Stages of the inverse problem and data assimilation

Answer 2

Question 3

CouplingMethodologies: Identification&estimation of states&parameters

2nd Step. Minimize the difference between the real and virtual asset, what do whe want to achieve

Answer 3

Minimize difference or minimize uncertainty? . This is done by generalized LEAST SQUARES PROBLEMS, two kind of solutions:

Question 4

CouplingMethodologies: Identification&estimation of states&parameters

How to get the PARAMETERS/STATE/ESTIMATION of the system

Answer 4

Different aspects influence how well this can be done
* System (model) – the model is less important than the physics of the
system!
* Excitation
* Sensors

Question 5

CouplingMethodologies: Identification&estimation of states&parameters

Which problems can we face with the IDENTIFICATION PROBLEM

Answer 5

We have different approaches:
*Time-domain
* Frequency-domain
* ‘feature’-domain

Question 6

Main challenge: How to practically couple various types of models?

Answer 6

• Challenging to generally exploit models defined in commercial software in these methodologies
  ——FMI/FMU has the potential to streamline this!
• Most of these algorithms require some hands-on programming still…

Question 7

Estimators and Observers

What is the purpose of Estimators and observers

Answer 7

Obtain information from meassurements (sensors), fusion sensors

Question 8

What is a linearobserver/estimator

Answer 8

Question 9

Explain. Extended Kalman Filter!!

Answer 9

https://nl.mathworks.com/support/search.html?fq%5B%5D=asset_type_name:video&fq%5B%5D=category:ident/online-state-estimation&page=1&s_tid=CRUX_topnav

Question 10

Difference between kinematic and dynamic model

Answer 10

Question 11

Conclusions, Observers / Estimators

Answer 11

Question 12

PARAMETER IDENTIFICATION

What is the difference between system identification VS parameter identification.
How to get the parameters?
What are the sources of information

Answer 12

System identification = To obtain the model of a system
Parameter identification = To obtain parameter values in that model

Question 13

Offline parameters what represent and what online parameters.
What is the goal of the parameters in the virtual replica

Answer 13

Offline: represents the behaviour and online : the changes of the physical system
We want that the parameters of the model be as match as possible the parameters of the real systems

Question 14

PARAMETER IDENTIFICATION

What is offline parameter identification, characteristics?

Answer 14

how to represent realistic behaiviour of the physical system: With good models + the right parameters values

Question 15

Diffferent ways to run offline tests

Answer 15

Sine sweeping: apply a senosoidal signal and you meassure the respons (freq) dom. this is for the dynamics of the system.

Question 16

PARAMETER IDENTIFICATION

What is the ON-LINE parameter identification, what do we want to reflect?—how to identify parameters of a system that is already in operation?

Answer 16

Here we want to REFLECT CHANGES in the model from the PS. if something happens in the PS here we should see them

Question 17

Examples of identification in a Two mass systems, and how to identify the parametrs of G

Answer 17

Question 18

How to represent a model, which function, how to find the parameters of the model when the system is online?

Answer 18

look for analogies, try to simulate with a two mass systems.
Look at the TRANSFER FUNCTION, this is the model!! this is the virtual replica. –Look at the parameters..Excite the system with PSEUDO RANDOM BINARY SIGNAL

Question 19

PARAMETER IDENTIFICATION

When and why to use OFFLINE or ONLINE parameter identification

Answer 19

Question 20

Digital Twin Verification and Validation

How to we check if there is consistancy between PA and VA?

Answer 20

-Focus on simulation models as Digital Twins
* The DT can consist of a number of models and configurations interacting
-Construct various models which can be used in different scenario’s to assess the behavior of the real asset

Question 21

Digital Twin Verification and Validation

What is Verification and Validadation. What should be verificate and validate

Answer 21

Verification: does the DT meet the requirements, eg. is the model correctly implemented.
Validation::does the DT meet the needs of the user, eg. Can we extract the desired quantities of interest, is the model accurate enough to extract value

Question 22

Digital Twin Verification and Validation

At which level and what should we verificate and validate

Answer 22

Model Element components and DT. Validate the algorithm and do test in different scenarios!.

Question 23

Digital Twin Verification and Validation

Which set of test give us Strong validation and Weak validation?

Answer 23

Be aware to separate the data sets: Trainig/Validation/data set

Question 24

Basics of uncertainty in Digital Twins

What is uncertainty in Digital Twins, where can there exists and which types

Answer 24