Results 61 to 70 of about 4,580 (209)

Safeguarded Reinforcement Learning for Dynamic Environments

open access: yesOptimal Control Applications and Methods, EarlyView.
This paper uses a combination of Reinforcement Learning and Funnel Control to train a fast and safe controller for systems operating in changing environments. Furthermore, the presented formulation overcomes former limitations associated with the need for predefined reference trajectories.
Simon Gottschalk
wiley   +1 more source

Data‐driven emulation of flow‐dependent background‐error variance in variational data assimilation

open access: yesQuarterly Journal of the Royal Meteorological Society, EarlyView.
A machine‐learning approach is developed to emulate flow‐dependent background‐error variance within a variational data assimilation framework. The method reproduces uncertainty information that would normally require a 50‐member ensemble using only five members, while maintaining comparable observation fit and forecast performance.
Wei Pan   +3 more
wiley   +1 more source

A Lipschitz condition along a transversal foliation implies local uniqueness for ODEs

open access: yesElectronic Journal of Qualitative Theory of Differential Equations, 2018
We prove the following result: if a continuous vector field $F$ is Lipschitz when restricted to the hypersurfaces determined by a suitable foliation and a transversal condition is satisfied at the initial condition, then $F$ determines a locally unique ...
José Ángel Cid, F. Adrián Tojo
doaj   +1 more source

Frequency‐Domain Analysis of External Signal Propagation Through Sliding Mode Control Systems With Dynamic Actuators

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT The importance of frequency domain methods in analysis and design of sliding mode (SM) control systems is mostly associated with chattering, where the advantages of these methods over state‐space and Lyapunov's methods are quite obvious.
I. M. Boiko
wiley   +1 more source

Exact Robust Filtering and Differentiation Based on Sliding Modes and Homogeneity

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This article addresses the problem of online estimation of the derivatives of a signal corrupted by measurement noise. The measured signal is modeled as the sum of a smooth nominal component and a uniformly bounded noise term. A key objective is to attenuate the effect of high‐frequency noise.
Jaime A. Moreno, Arie Levant
wiley   +1 more source

A measure theoretic approach to Lipschitz regularity and its Haar type wavelet analysis

open access: yesMathematical Modelling and Analysis
The $\alpha$−Lipschitz character of a time series or an image summarizes, in the single parameter α, some persistence properties of the original function modeling the given signal.
Hugo Aimar, Juliana Boasso
doaj   +1 more source

Gradient‐ and Newton‐Based Unit Vector Extremum Seeking Control

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This paper proposes new methods for stable and efficient convergence in multivariable extremum seeking control (ESC) using sliding mode techniques. Inspired by classical sliding modes and finite‐time control, the approach integrates these ideas into gradient‐ and Newton‐based ESC schemes with sinusoidal perturbations.
Roberto Luo   +3 more
wiley   +1 more source

Lipschitz extension theorems with explicit constants

open access: yesAnalysis and Geometry in Metric Spaces
In this mostly expository article, we give streamlined proofs of several well-known Lipschitz extension theorems. We pay special attention to obtaining statements with explicit expressions for the extension constants.
Basso Giuliano
doaj   +1 more source

Validation of Neural Network Controllers for Uncertain Systems Using the Keep‐Close Approach: Robustness Analysis and Safety Verification

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT The safety verification of neural network (NN) controllers operating in uncertain environments characterized by unmodeled dynamics, nonlinearities, and time delays remains a fundamental challenge in robust control analysis. This article introduces a novel method, termed Keep‐Close, for analyzing the performance and robustness of uncertain ...
Abdelhafid Zenati, Nabil Aouf
wiley   +1 more source

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