arXiv Machine Learning

Integral Formulation of QENDy for Robust Nonlinear System Identification

arXiv:2606. 11629v1 Announce Type: cross Abstract: This manuscript proposes an integral formulation of the newly defined quadratic embedding method for identifying nonlinear systems (QENDy).

arXiv Machine Learning
Sep 3

Sample Complexity of Linear Quadratic Regulator Without Initial Stability

The paper proposes a new receding‑horizon algorithm for the Linear Quadratic Regulator (LQR) with unknown dynamics, inspired by REINFORCE. It removes the need for two‑point gradient estimates and does not require a stable initial policy, while maintaining the same order of sample complexity. A refined analysis of error propagation via the Riccati operator’s contraction under Riemannian distance yields improved sample complexity and convergence guarantees.

By Amirreza Neshaei Moghaddam, Alex Olshevsky, Bahman Gharesifard
arXiv AI
Sep 7

Data-Driven Learning of Unknown Nonlinear Differential Equations Using Functional Analysis

The paper proposes a new interpretable machine learning approach for discovering unknown nonlinear ordinary differential equations from a single state trajectory. It differs from existing methods by deriving its formulation from Functional Analysis and Operator Theory and by defining a cost function as an integral distance between functions rather than a discrete error sum. An incremental learning algorithm enables online updates, allowing simultaneous identification of both system dynamics and external time‑varying forces, with numerical examples illustrating its benefits.

By Seyyed Shaho Alaviani, Yongzhi Qu, Gregory W. Vogl
arXiv Statistics ML
2d ago

Optimal Centered Active Excitation in Linear System Identification

The paper introduces an active learning algorithm for linear system identification that uses optimal centered noise excitation. It employs ordinary least squares and semidefinite programming to achieve minimal sample complexity while enabling efficient computation of the system matrix estimate. The authors provide both lower and upper bounds on sample complexity that match up to universal factors and explicitly depend on system parameters such as state dimension.

By Kaito Ito, Alexandre Proutiere