Invited Talk at Seoul National University by Michael Schuster 24. März 20255. Mai 2025 Title: Probabilistic Contsrained Optimization with ODEs and PDEs Abstract: Uncertainty often plays an important role in gas transport and probabilistic constraints are an excellent modeling tool to obtain controls and other quantities that are robust against perturbations. To efficiently evaluate the probabilistic constraint, we present an approach based on kernel density estimation, such that the probabilistic constrained optimization problem can be considered as classical nonllinear problem, allowing us to apply classical nonlinear optimization theory.As an application, we consider and analyze the steady state and the transient gas flow in pipeline networks. We introduce the modelling based on the isothermal Euler equations including random boundary data, leading to optimal control problems with probabilistic constraints. Schuster_Seoul2025
Seminar by Jan Giesselmann 21. März 202521. März 2025 Jan Giesselmann gave a seminar on „Energy consistent methods for port-Hamiltonian systems“ at the Computational Mathematics Seminar at Technical University of Hamburg. The talk took place via zoom, the host was Daniel Ruprecht.
Session Talk at SIGOPT 2025 by Michael Schuster 4. März 20255. Mai 2025 Michael Schuster gave a talk at SIGOPT – International Conference on Optimization, 04.-06. March 2025 in Siegen. Title: The Location Problem for Compressor Stations in Pipeline Networks In the operation of pipeline networks, compressors play a crucial role in ensuring the network’s functionality for various scenarios. In this contribution we address the important question of finding the optimal location of the compressors. That results in non-convex mixed integer stochastic optimization problems with probabilistic constraints.Using a steady state model for the gas flow in pipeline networks including compressor control and uncertain loads given by certain probability distributions, the problem of finding the optimal location for the control on the network, s.t. the control cost is minimal and the gas pressure stays within given bounds, is considered.In the deterministic setting, explicit bounds for the pipe length and the inlet pressure, s.t. a unique optimal compressor location with minimal control cost exists, are presented. In the probabilistic setting, an existence result for the optimal compressor location is presented and the uniqueness of the solution is discussed depending on the probability distribution.Further the problem of finding the optimal compressor locations on networks including the number of compressor stations as variable is considered. Results for the existence of optimal locations on a graph in both, the deterministic and the probabilistic setting, are presented. The paper concludes with an illustrative example on a diamond graph demonstrating that the minimal number of compressor stations is not necessarily equal to the optimal number. slides_Schuster_sigopt25
Minisymposium talks by Martin Gugat and Jan Giesselmann 30. Dezember 2024 Martin Gugat and Jan Giesselmann gave presentations at the „Mathematics and Decision Conference „, which was held at UM6P University, Benguerir, Morocco, within the minisymposium on „Control and Applications“ which was organised by Abeladim Elakri, Lahcen Maniar and Enrique Zuazua. They presented research on „Data assimilation for gas flows via observers using distributed measurements“ (Jan Giesselmann) and „Synchronization of observer systems for the flow in gas networks“ (Martin Gugat).
Seminar by Martin Gugat: An introduction to the turnpike phenomenon 18. November 202419. November 2024 On November 28, Martin Gugat will give a lecture in Aachen for the graduate school EDDy (Energy, Entropy, and Dissipative Dynamics). The lecture with the title ‚An introduction to the turnpike phenomenon with examples and links to recent results‘ will take place from 10:45 to 11:45 am, at Pontdriesch 14, room 008 SeMath (host: Michael Herty). Click here for the announcement!
MOG 2024 Mathematics of Gas Transport and Energy 11. Oktober 202430. Oktober 2024 On October 10th and 11th, 2024, we organized the fourth edition of the international conference „Mathematics of Gas Transport and Energy (MOG)“ in the historic city of Regensburg, Germany.The two-day conference focused on connecting leading experts in applied mathematics with leading stakeholders from the industry and the public sector concerned with the energy system’s transition. We had fruitful discussions between academic partners and representatives from other sectors on today´s broad challenges in the energy sector, taking into account the transition from natural gas to hydrogen networks, its coupling with electricity, and related topics.Invited speakers: 🔹 Miguel Anjos (University of Edinburgh) 🔹 Merve Bodur (University of Edinburgh) 🔹 Ronaldo M. Colombo (University of Brescia) 🔹 Jochen Deuerlein (3S Consult) 🔹 Timm Faulwasser (TU Hamburg) 🔹 Simone Göttlich (University of Mannheim) 🔹 Holger Heitsch (WIAS Berlin) 🔹 Erich Maurer (Energieagentur Nordbayern) 🔹 Jaap Pedersen (Zuse Institute Berlin) 🔹 Lena Salm (TenneT TSO) 🔹 Johannes Schiffer (BTU Cottbus) 🔹 Tom Streubel (PSI Software) 🔹 Martin Styblo (PSIG) 🔹 Tabea Tscherpel (TU Darmstadt) 🔹 Ann-Kathrin Wiertz (FAU Erlangen-Nürnberg)Thanks to all speakers, attendees, and the organizing team from the CRC TRR 154, funded by the German Science Foundation, for making this event possible!
Poster Presentation at 2024 Conference on Control, Inversion and Numerics for PDEs, Fudan University, Shanghai, China 10. Oktober 202411. November 2024 From October 8–10, 2024, Michael Schuster presented a poster on the topic „Nodal Control and the Turnpike Phenomenon“ during the 2024 Conference on Control, Inversion, and Numerics for PDEs, held at Fudan University in Shanghai, China About the project: The goal of this project is to prove turnpike results for optimal control problems in gas networks. We will consider nodal control since the control action takes place at compressors that are located at a small number of points in the networks. Probabilistic constraints are included since they allow to take into account the uncertainty of e.g. the customer demand. We will also scrutinize switching conditions that arise e.g in the decision to to open or close a gas valve. Since the turnpike phenomenon relates the dynamic optimal states to steady states, we will also study steady gas flows on networks with intertwined cycles (view the poster here).
Invited Talk at Seoul National University (SNU), Seoul, South Korea 2. Oktober 20243. November 2024 The talk about „Optimal Control for ODEs and PDEs: The Turnpike Phenomenon“ was invited by Prof. Seung-Yeal Ha and Prof. Dongnam Ko.The turnpike phenomenon for dynamic optimal control problems provide insights about the relation between the dynamic optimal control and the solution of the corresponding static optimal control problem. In this talk we give an overview about different turnpike structures for optimal control problems with ordinary differential equations (ODEs) and partial differential equations (PDEs).For optimal control problems with ODEs an exponential turnpike inequality can be shown by basic control theory. These results can be extended to an integral turnpike inequality for optimal control problems with linear hyperbolic systems. For an optimal control problem with non differential tracking term in the objective function, that is exactly controllable, we can show under certain assumptions that the optimal system state is steered exactly to the desired state after finite time. Further we consider an optimal control problem for a hyperbolic system with random boundary data and we show the existence of optimal controls. A turnpike property for hyperbolic systems with random boundary data can be shown numerically.
Christine Bernardi Lecture 29. September 202430. Dezember 2024 The TRR 154 and the department of mathematics of TU Darmstadt organize jointly a series of annual lectures in honor of Christine Bernadi, an inspiring female applied mathematician. 23 October 2024, 5:15 pm: „Mathematics of Nonlinear Acoustics: Modeling – Analysis – Numerics – Inverse Problems“ by Barbara Kaltenbacher. Link: https://www.mathematik.tu-darmstadt.de/fb/aktuelles/christine_bernardi_lectures/christine_bernardi_lectures.de.jsp