arXiv Machine Learning

Neural Closed-Loop Identification of Nonlinear Systems with Stability and Generalization Guarantees

arXiv AI
Oct 12

In-Context Learning for System Identification: Probabilistic Formulation, Long-Sequence Handling, and Benchmark Validation

The paper presents an in-context learning framework for system identification that replaces traditional two-step model estimation with a meta model mapping training data and query inputs directly to outputs. It introduces a probabilistic Transformer-based architecture capable of handling long training sequences and producing calibrated predictions over extended horizons. Additionally, the authors demonstrate that a pre-trained meta model can generate uncertainty-aware synthetic data to aid classical identification methods and validate their approach on standard nonlinear benchmarks and challenging out-of-distribution scenarios, achieving competitive accuracy and strong generalization.

By Matteo Rufolo, Dario Piga, Filippo Pura, Marco Forgione
arXiv Machine Learning
Jun 4

Certified Neural Approximations of Nonlinear Dynamics

arXiv:2505. 15497v3 Announce Type: replace Abstract: Neural networks hold great potential to act as approximate models of nonlinear dynamical systems, with the resulting neural approximations enabling verification and control of such systems.

By Frederik Baymler Mathiesen, Nikolaus Vertovec, Francesco Fabiano, Luca Laurenti, Alessandro Abate
arXiv Machine Learning
Aug 27

Non-Asymptotic Bounds for Closed-Loop Identification of Sub-Exponentially Growing Nonlinear Stochastic Systems

The paper studies least squares parameter estimation for discrete‑time, unstable, closed‑loop nonlinear stochastic systems with linearly parametrised uncertainty and additive i.i.d. process noise. By perturbing the control policy with exploratory input and assuming a sub‑exponential input‑to‑state growth property, the authors derive non‑asymptotic bounds on the estimation error whenever the state trajectory remains in an informative region of the state space. When the entire state space is informative, the bounds hold with high probability for all time steps, and the authors illustrate the applicability of their results with examples that extend beyond existing work.

By Seth Siriya, Jingge Zhu, Dragan Ne\v{s}i\'c, Ye Pu
arXiv Machine Learning
Oct 16

Learning Changes the World and Then What Was Learned has Changed: Training and Deploying Neural Networks in the Control Loop

The paper discusses how offline-trained neural networks, when used in closed-loop control systems, can change the state distribution they were trained on, leading to performance degradation. It introduces a taxonomy of failure modes—Closed-Loop Identification Error, deployment-induced Action Error, and continuous Tracking Error—and uses discrete-time sensitivity analysis to explain how these errors arise. The authors propose time-scale separated online adaptation policies to mitigate distribution shift, validated on a nonlinear Duffing oscillator, showing that bounded continuous learning can prevent trajectory divergence while static deployments cannot.

By Vittorio Lippi
arXiv Machine Learning
Oct 22

Certified Neural Approximation of Robust Nonlinear Model Predictive Control

The paper presents a framework for creating neural network controllers that inherit the safety and stability guarantees of a robust model predictive control (MPC) policy. By treating the neural network’s approximation error as a bounded input disturbance and incorporating it into the MPC design, the method ensures recursive feasibility and stability before deployment. The approach is offline and constructive, requiring only Lipschitz bounds, and simulations show the learned controller matches the original MPC’s closed‑loop behavior while reducing online computation.

By Hendrik Alsmeier, Maik Pfefferkorn, Rolf Findeisen