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An analogy
WHAT IS SURROGATE MODELLING?
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Real rabbit
Detailed rabbit simulator (model)
Surrogate model 2 Surrogate model 3 Surrogate model 1
Urban Drainage Systems PhD Candidate: Mahmood Mahmoodian Daily - - PowerPoint PPT Presentation
Urban Drainage Systems PhD Candidate: Mahmood Mahmoodian Daily - - PowerPoint PPT Presentation
Surrogate Modelling for Urban Drainage Systems PhD Candidate: Mahmood Mahmoodian Daily supervisor: Ulrich Leopold WHAT IS SURROGATE MODELLING? An analogy Detailed rabbit simulator (model) Real rabbit Surrogate model 1 Surrogate model 2
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MY CHALLENGE
Urban Drainage System
Computationally expensive for:
- Real-time control (RTC)
- Calibration
- Optimisation
- Uncertainty propagation
Zoom in Modelling
WWTP
Storage Tank 1 Storage Tank 2
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To obtain fast simulators
POSSIBLE SOLUTIONS:
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Develop a surrogate of already existing simulators (e.g. InfoWorks,…)
- 1. Data-driven approaches
- 2. Projection-based approaches
- 3. Hierarchical or multi-fidelity approaches
- 4. Hybrid approaches
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METHOD 2: A DATA-DRIVEN APPROACH
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GAUSSIAN PROCESS EMULATOR (GPE) Main advantages:
- Non-intrusive and generic method
- Uncertainty quantification
Main disadvantages:
- Limited number of parameters
- Short simulations
Validation Training data:
Olson & Chang (2013)
Y: model output of interest µβ : a mean function which is considered linear in time ξy : a vector of covariance matrix parameters. Validation
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METHOD 2: A HYBRID METHOD (MODEL-DRIVEN + DATA-DRIVEN)
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Model-driven Data-driven
Storage Tank Volume Change:
Main advantages:
- Super fast! (1400 times faster)
- Useful for longer simulations
Main disadvantages:
- Partly-intrusive and case-specific
- Uncertainty quantification?
Validation
mass balance
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TAKE AWAY MESSAGE
There is NO generic remedy of surrogate modelling for all applications Selection criteria:
- 1. Reduce the runtime significantly
- 2. Give a quantification of the uncertainty
- 3. Be easily applicable in practice
Example: real-time control (RTC) Data-driven GPE approach!
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THANK YOU FOR YOUR ATTENTION!
Keep It as Simple as Possible! (Law of parsimony, Ockham's Razor) Email: mahmood.mahmoodian@list.lu
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PARTNERS AND ACKNOWLEDGEMENTS
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 607000.