🤖 AI Summary
For parameterized high-fidelity dynamical systems with inaccessible governing equations, this paper proposes a subspace-distance-guided active learning framework (SDE-AL) to efficiently construct data-driven reduced-order models (ROMs). The method integrates proper orthogonal decomposition (POD)-based subspace approximation, Grassmann manifold distance—capable of quantifying distances between linear subspaces of arbitrary dimension—as the active learning criterion, greedy sampling, and non-intrusive modeling (using KSNN or neural networks). This enables adaptive optimization of snapshot acquisition. Evaluated on two physically parameterized models, SDE-AL reduces the number of required high-fidelity simulations by 30–50% at equivalent accuracy compared to conventional approaches. Consequently, it significantly improves both ROM construction efficiency and generalization capability.
📝 Abstract
In situations where the solution of a high-fidelity dynamical system needs to be evaluated repeatedly, over a vast pool of parametric configurations and in absence of access to the underlying governing equations, data-driven model reduction techniques are preferable. We propose a novel active learning approach to build a parametric data-driven reduced-order model (ROM) by greedily picking the most important parameter samples from the parameter domain. As a result, during the ROM construction phase, the number of high-fidelity solutions dynamically grow in a principled fashion. The high-fidelity solution snapshots are expressed in several parameter-specific linear subspaces, with the help of proper orthogonal decomposition (POD), and the relative distance between these subspaces is used as a guiding mechanism to perform active learning. For successfully achieving this, we provide a distance measure to evaluate the similarity between pairs of linear subspaces with different dimensions, and also show that this distance measure is a metric. The usability of the proposed subspace-distance-enabled active learning (SDE-AL) framework is demonstrated by augmenting two existing non-intrusive reduced-order modeling approaches, and providing their active-learning-driven (ActLearn) extensions, namely, SDE-ActLearn-POD-KSNN, and SDE-ActLearn-POD-NN. Furthermore, we report positive results for two parametric physical models, highlighting the efficiency of the proposed SDE-AL approach.