Data-driven identification of latent port-Hamiltonian systems

Fuente: arXiv
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Autori principali: Rettberg, Johannes, Kneifl, Jonas, Herb, Julius, Buchfink, Patrick, Fehr, Jörg, Haasdonk, Bernard
Natura: Preprint
Pubblicazione: 2024
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author Rettberg, Johannes
Kneifl, Jonas
Herb, Julius
Buchfink, Patrick
Fehr, Jörg
Haasdonk, Bernard
author_facet Rettberg, Johannes
Kneifl, Jonas
Herb, Julius
Buchfink, Patrick
Fehr, Jörg
Haasdonk, Bernard
contents Conventional physics-based modeling techniques involve high effort, e.g., time and expert knowledge, while data-driven methods often lack interpretability, structure, and sometimes reliability. To mitigate this, we present a data-driven system identification framework that derives models in the port-Hamiltonian (pH) formulation. This formulation is suitable for multi-physical systems while guaranteeing the useful system theoretical properties of passivity and stability. Our framework combines linear and nonlinear reduction with structured, physics-motivated system identification. In this process, high-dimensional state data obtained from possibly nonlinear systems serves as input for an autoencoder, which then performs two tasks: (i) nonlinearly transforming and (ii) reducing this data onto a low-dimensional latent space. In this space, a linear pH system, that satisfies the pH properties per construction, is parameterized by the weights of a neural network. The mathematical requirements are met by defining the pH matrices through Cholesky factorizations. The neural networks that define the coordinate transformation and the pH system are identified in a joint optimization process to match the dynamics observed in the data while defining a linear pH system in the latent space. The learned, low-dimensional pH system can describe even nonlinear systems and is rapidly computable due to its small size. The method is exemplified by a parametric mass-spring-damper and a nonlinear pendulum example, as well as the high-dimensional model of a disc brake with linear thermoelastic behavior.
format Preprint
id arxiv_https___arxiv_org_abs_2408_08185
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Data-driven identification of latent port-Hamiltonian systems
Rettberg, Johannes
Kneifl, Jonas
Herb, Julius
Buchfink, Patrick
Fehr, Jörg
Haasdonk, Bernard
Dynamical Systems
Machine Learning
93B30, 37E99
Conventional physics-based modeling techniques involve high effort, e.g., time and expert knowledge, while data-driven methods often lack interpretability, structure, and sometimes reliability. To mitigate this, we present a data-driven system identification framework that derives models in the port-Hamiltonian (pH) formulation. This formulation is suitable for multi-physical systems while guaranteeing the useful system theoretical properties of passivity and stability. Our framework combines linear and nonlinear reduction with structured, physics-motivated system identification. In this process, high-dimensional state data obtained from possibly nonlinear systems serves as input for an autoencoder, which then performs two tasks: (i) nonlinearly transforming and (ii) reducing this data onto a low-dimensional latent space. In this space, a linear pH system, that satisfies the pH properties per construction, is parameterized by the weights of a neural network. The mathematical requirements are met by defining the pH matrices through Cholesky factorizations. The neural networks that define the coordinate transformation and the pH system are identified in a joint optimization process to match the dynamics observed in the data while defining a linear pH system in the latent space. The learned, low-dimensional pH system can describe even nonlinear systems and is rapidly computable due to its small size. The method is exemplified by a parametric mass-spring-damper and a nonlinear pendulum example, as well as the high-dimensional model of a disc brake with linear thermoelastic behavior.
title Data-driven identification of latent port-Hamiltonian systems
topic Dynamical Systems
Machine Learning
93B30, 37E99
url https://arxiv.org/abs/2408.08185