Search Results for author: Roland Tóth

Found 50 papers, 4 papers with code

Learning-based model augmentation with LFRs

no code implementations2 Apr 2024 Jan H. Hoekstra, Chris Verhoek, Roland Tóth, Maarten Schoukens

This model structure is able to represent many common model augmentation structures, thus unifying them under the proposed model structure.

On the reduction of Linear Parameter-Varying State-Space models

no code implementations2 Apr 2024 E. Javier Olucha, Bogoljub Terzin, Amritam Das, Roland Tóth

This paper presents an overview and comparative study of the state of the art in State-Order Reduction (SOR) and Scheduling Dimension Reduction (SDR) for Linear Parameter-Varying (LPV) State-Space (SS) models, comparing and benchmarking their capabilities, limitations and performance.

Benchmarking Dimensionality Reduction +1

Decoupling parameter variation from noise: Biquadratic Lyapunov forms in data-driven LPV control

no code implementations25 Mar 2024 Chris Verhoek, Jaap Eising, Florian Dörfler, Roland Tóth

A promising step from linear towards nonlinear data-driven control is via the design of controllers for linear parameter-varying (LPV) systems, which are linear systems whose parameters are varying along a measurable scheduling signal.

LEMMA Scheduling

Unconstrained Parameterization of Stable LPV Input-Output Models: with Application to System Identification

no code implementations18 Jan 2024 Johan Kon, Jeroen van de Wijdeven, Dennis Bruijnen, Roland Tóth, Marcel Heertjes, Tom Oomen

Ensuring stability of discrete-time (DT) linear parameter-varying (LPV) input-output (IO) models estimated via system identification methods is a challenging problem as known stability constraints can only be numerically verified, e. g., through solving Linear Matrix Inequalities.

State Derivative Normalization for Continuous-Time Deep Neural Networks

no code implementations5 Jan 2024 Jonas Weigand, Gerben I. Beintema, Jonas Ulmen, Daniel Görges, Roland Tóth, Maarten Schoukens, Martin Ruskowski

However, in continuous-time state-space model estimation, it has been observed that improper normalization of either the hidden state or hidden state derivative of the model estimate, or even of the time interval can lead to numerical and optimization challenges with deep learning based methods.

Learning Reduced-Order Linear Parameter-Varying Models of Nonlinear Systems

1 code implementation11 Dec 2023 Patrick J. W. Koelewijn, Rajiv Sing, Peter Seiler, Roland Tóth

In this paper, we consider the learning of a Reduced-Order Linear Parameter-Varying Model (ROLPVM) of a nonlinear dynamical system based on data.

A Linear Parameter-Varying Approach to Data Predictive Control

no code implementations13 Nov 2023 Chris Verhoek, Julian Berberich, Sofie Haesaert, Roland Tóth, Hossam S. Abbas

By means of the linear parameter-varying (LPV) Fundamental Lemma, we derive novel data-driven predictive control (DPC) methods for LPV systems.

LEMMA

Attitude Takeover Control for Noncooperative Space Targets Based on Gaussian Processes with Online Model Learning

no code implementations24 Oct 2023 YuHan Liu, Pengyu Wang, Chang-Hun Lee, Roland Tóth

One major challenge for autonomous attitude takeover control for on-orbit servicing of spacecraft is that an accurate dynamic motion model of the combined vehicles is highly nonlinear, complex and often costly to identify online, which makes traditional model-based control impractical for this task.

Gaussian Processes

Direct Learning for Parameter-Varying Feedforward Control: A Neural-Network Approach

no code implementations22 Sep 2023 Johan Kon, Jeroen van de Wijdeven, Dennis Bruijnen, Roland Tóth, Marcel Heertjes, Tom Oomen

The aim of this paper is to develop an input-output linear parameter-varying (LPV) feedforward parameterization and a corresponding data-driven estimation method in which the dependency of the coefficients on the scheduling signal are learned by a neural network.

Scheduling

Equilibrium-Independent Control of Continuous-Time Nonlinear Systems via the LPV Framework -- Extended Version

no code implementations16 Aug 2023 Patrick J. W. Koelewijn, Siep Weiland, Roland Tóth

Additionally, we compare the proposed method to a standard LPV control design, demonstrating the improved stability and performance guarantees of the new approach.

Meta-State-Space Learning: An Identification Approach for Stochastic Dynamical Systems

1 code implementation13 Jul 2023 Gerben I. Beintema, Maarten Schoukens, Roland Tóth

Available methods for identification of stochastic dynamical systems from input-output data generally impose restricting structural assumptions on either the noise structure in the data-generating system or the possible state probability distributions.

Physics-Informed Learning Using Hamiltonian Neural Networks with Output Error Noise Models

no code implementations2 May 2023 Sarvin Moradi, Nick Jaensson, Roland Tóth, Maarten Schoukens

Hamiltonian Neural Networks (HNNs) implement Hamiltonian theory in deep learning and form a comprehensive framework for modeling autonomous energy-conservative systems.

Direct data-driven control with signal temporal logic specifications

no code implementations5 Apr 2023 Birgit C. van Huijgevoort, Chris Verhoek, Roland Tóth, Sofie Haesaert

Most control synthesis methods under temporal logic properties require a model of the system, however, identifying such a model can be a challenging task.

Learning Stable and Robust Linear Parameter-Varying State-Space Models

no code implementations4 Apr 2023 Chris Verhoek, Ruigang Wang, Roland Tóth

This paper presents two direct parameterizations of stable and robust linear parameter-varying state-space (LPV-SS) models.

Initialization Approach for Nonlinear State-Space Identification via the Subspace Encoder Approach

no code implementations4 Apr 2023 Rishi Ramkannan, Gerben I. Beintema, Roland Tóth, Maarten Schoukens

The SUBNET neural network architecture has been developed to identify nonlinear state-space models from input-output data.

Computationally efficient predictive control based on ANN state-space models

no code implementations30 Mar 2023 Jan H. Hoekstra, Bence Cseppentő, Gerben I. Beintema, Maarten Schoukens, Zsolt Kollár, Roland Tóth

Artificial neural networks (ANN) have been shown to be flexible and effective function estimators for identification of nonlinear state-space models.

Model Predictive Control

Exploring the use of deep learning in task-flexible ILC

no code implementations25 Mar 2023 Anantha Sai Hariharan Vinjarapu, Yorick Broens, Hans Butler, Roland Tóth

To benchmark the performance of the proposed approach, a simulation study is presented which compares the TAIL-ILC to classical model-based feedforward strategies and existing learning-based approaches, such as neural network based feedforward learning.

Imitation Learning

On Improved Commutation for Moving-Magnet Planar Actuators

no code implementations25 Mar 2023 Yorick Broens, Hans Butler, Roland Tóth

The demand for high-precision and high-throughput motion control systems has increased significantly in recent years.

Position

Direct data-driven state-feedback control of general nonlinear systems

no code implementations19 Mar 2023 Chris Verhoek, Patrick J. W. Koelewijn, Sofie Haesaert, Roland Tóth

Through the use of the Fundamental Lemma for linear systems, a direct data-driven state-feedback control synthesis method is presented for a rather general class of nonlinear (NL) systems.

LEMMA Scheduling

Data-driven Dissipativity Analysis of Linear Parameter-Varying Systems

no code implementations17 Mar 2023 Chris Verhoek, Julian Berberich, Sofie Haesaert, Frank Allgöwer, Roland Tóth

We derive direct data-driven dissipativity analysis methods for Linear Parameter-Varying (LPV) systems using a single sequence of input-scheduling-output data.

Scheduling

Finite Dimensional Koopman Form of Polynomial Nonlinear Systems

no code implementations16 Jan 2023 Lucian Cristian Iacob, Maarten Schoukens, Roland Tóth

The Koopman framework is a popular approach to transform a finite dimensional nonlinear system into an infinite dimensional, but linear model through a lifting process, using so-called observable functions.

Direct data-driven LPV control of nonlinear systems: An experimental result

no code implementations30 Nov 2022 Chris Verhoek, Hossam S. Abbas, Roland Tóth

The LPV data-driven control design that builds on this representation form uses only measurement data from the nonlinear system and a priori information on a scheduling map that can lead to an LPV embedding of the nonlinear system behavior.

Scheduling

Direct Data-Driven State-Feedback Control of Linear Parameter-Varying Systems

no code implementations30 Nov 2022 Chris Verhoek, Roland Tóth, Hossam S. Abbas

We derive novel methods that allow to synthesize LPV state-feedback controllers directly from a single sequence of data and guarantee stability and performance of the closed-loop system, without knowing the model of the plant.

Scheduling

Learning For Predictive Control: A Dual Gaussian Process Approach

no code implementations7 Nov 2022 YuHan Liu, Pengyu Wang, Roland Tóth

Gaussian process (GP) based estimation of system models is an effective tool to learn unknown dynamics directly from input/output data.

Model Predictive Control

Deep Subspace Encoders for Nonlinear System Identification

no code implementations26 Oct 2022 Gerben I. Beintema, Maarten Schoukens, Roland Tóth

In this paper, we aim to overcome these issues by proposing a method which uses a truncated prediction loss and a subspace encoder for state estimation.

Time Series Time Series Analysis

On modal observers for beyond rigid body $H_\infty$ control in high-precision mechatronics

no code implementations14 Sep 2022 Yorick Broens, Hans Butler, Roland Tóth

The ever increasing need for performance results in increasingly rigorous demands on throughput and positioning accuracy of high-precision motion systems, which often suffer from position dependent effects that originate from relative actuation and sensing of the moving-body.

Position

Koopman Form of Nonlinear Systems with Inputs

no code implementations25 Jul 2022 Lucian Cristian Iacob, Roland Tóth, Maarten Schoukens

In applications for systems with inputs, generally a linear time invariant (LTI) form of the Koopman model is assumed, as it facilitates the use of control techniques such as linear quadratic regulation and model predictive control.

Model Predictive Control

Optimal Synthesis of LTI Koopman Models for Nonlinear Systems with Inputs

no code implementations15 Jun 2022 Lucian Cristian Iacob, Roland Tóth, Maarten Schoukens

In the lifted space, the dynamics are linear and represented by a so-called Koopman operator.

LPV Modeling of the Atmospheric Flight Dynamics of a Generic Parafoil Return Vehicle

no code implementations19 May 2022 Matthis H. de Lange, Chris Verhoek, Valentin Preda, Roland Tóth

Obtaining models that can be used for control is of utmost importance to ensure the guidance and navigation of spacecraft, like a Generic Parafoil Return Vehicle (GPRV).

Continuous-time identification of dynamic state-space models by deep subspace encoding

1 code implementation20 Apr 2022 Gerben I. Beintema, Maarten Schoukens, Roland Tóth

Continuous-time (CT) modeling has proven to provide improved sample efficiency and interpretability in learning the dynamical behavior of physical systems compared to discrete-time (DT) models.

LPV sequential loop closing for high-precision motion systems

no code implementations15 Mar 2022 Yorick Broens, Hans Butler, Roland Tóth

Increasingly stringent throughput requirements in the industry necessitate the need for lightweight design of high-precision motion systems to allow for high accelerations, while still achieving accurate positioning of the moving-body.

Position Vocal Bursts Intensity Prediction

On discretization of continuous-time LPV control solutions

no code implementations4 Feb 2022 Yorick Broens, Hans Butler, Roland Tóth

However, the main complication of CT synthesis approaches is the successive implementation of the resulting CT control solutions on physical hardware.

Learning Based Model Predictive Control for Quadcopters with Dual Gaussian Process

no code implementations22 Dec 2021 YuHan Liu, Roland Tóth

In this paper, we present a novel Dual Gaussian Process (DGP) based model predictive control strategy that improves the performance of a quadcopter during trajectory tracking.

Model Predictive Control

Deep Identification of Nonlinear Systems in Koopman Form

no code implementations6 Oct 2021 Lucian Cristian Iacob, Gerben Izaak Beintema, Maarten Schoukens, Roland Tóth

The present paper treats the identification of nonlinear dynamical systems using Koopman-based deep state-space encoders.

Frequency-Domain Data-Driven Controller Synthesis for Unstable LPV Systems

no code implementations20 Jul 2021 Tom Bloemers, Roland Tóth, Tom Oomen

Synthesizing controllers directly from frequency-domain measurement data is a powerful tool in the linear time-invariant framework.

Nonlinear Tracking and Rejection using Linear Parameter-Varying Control

no code implementations20 Apr 2021 Patrick J. W. Koelewijn, Roland Tóth, Henk Nijmeijer, Siep Weiland

The Linear Parameter-Varying (LPV) framework has been introduced with the intention to provide stability and performance guarantees for analysis and controller synthesis for Nonlinear (NL) systems via convex methods.

Nonlinear parameter-varying state-feedback design for a gyroscope using virtual control contraction metrics

no code implementations11 Apr 2021 Ruigang Wang, Patrick J. W. Koelwijn, Ian R. Manchester, Roland Tóth

In this paper, we present a virtual control contraction metric (VCCM) based nonlinear parameter-varying (NPV) approach to design a state-feedback controller for a control moment gyroscope (CMG) to track a user-defined trajectory set.

Data-Driven Predictive Control for Linear Parameter-Varying Systems

no code implementations30 Mar 2021 Chris Verhoek, Hossam S. Abbas, Roland Tóth, Sofie Haesaert

Based on the extension of the behavioral theory and the Fundamental Lemma for Linear Parameter-Varying (LPV) systems, this paper introduces a Data-driven Predictive Control (DPC) scheme capable to ensure reference tracking and satisfaction of Input-Output (IO) constraints for an unknown system under the conditions that (i) the system can be represented in an LPV form and (ii) an informative data-set containing measured IO and scheduling trajectories of the system is available.

LEMMA Scheduling

Fundamental Lemma for Data-Driven Analysis of Linear Parameter-Varying Systems

no code implementations30 Mar 2021 Chris Verhoek, Roland Tóth, Sofie Haesaert, Anne Koch

Based on the behavioural framework for LPV systems, we prove that one can obtain a result similar to Willems'.

LEMMA

LPV Modeling of Nonlinear Systems: A Multi-Path Feedback Linearization Approach

no code implementations26 Mar 2021 Hossam S. Abbas, Roland Tóth, Mihály Petreczky, Nader Meskin, Javad Mohammadpour Velni, Patrick J. W. Koelewijn

In the SISO case, all nonlinearities of the original system are embedded into one NL function, which is factorized, based on a proposed algorithm, to construct an LPV representation of the original NL system.

Scheduling

Incremental Stability and Performance Analysis of Discrete-Time Nonlinear Systems using the LPV Framework

no code implementations19 Mar 2021 Patrick J. W. Koelewijn, Roland Tóth

By embedding nonlinear systems in an LPV representation, the convex tools of the LPV framework can be applied to nonlinear systems for convex dissipativity based analysis and controller synthesis.

Convex Incremental Dissipativity Analysis of Nonlinear Systems - Extended version

no code implementations25 Jun 2020 Chris Verhoek, Patrick J. W. Koelewijn, Sofie Haesaert, Roland Tóth

We investigate how stability and performance characterizations of nonlinear systems in the incremental framework are linked to dissipativity, and how general performance characterization beyond the $\mathcal{L}_2$-gain concept can be understood in this framework.

Virtual Control Contraction Metrics: Convex Nonlinear Feedback Design via Behavioral Embedding

no code implementations18 Mar 2020 Ruigang Wang, Roland Tóth, Patrick J. W. Koelwijn, Ian R. Manchester

This paper presents a systematic approach to nonlinear state-feedback control design that has three main advantages: (i) it ensures exponential stability and $ \mathcal{L}_2 $-gain performance with respect to a user-defined set of reference trajectories, and (ii) it provides constructive conditions based on convex optimization and a path-integral-based control realization, and (iii) it is less restrictive than previous similar approaches.

SMOKE: Single-Stage Monocular 3D Object Detection via Keypoint Estimation

3 code implementations24 Feb 2020 Zechen Liu, Zizhang Wu, Roland Tóth

Estimating 3D orientation and translation of objects is essential for infrastructure-less autonomous navigation and driving.

Autonomous Navigation Keypoint Estimation +4

A Tree Adjoining Grammar Representation for Models Of Stochastic Dynamical Systems

no code implementations15 Jan 2020 Dhruv Khandelwal, Maarten Schoukens, Roland Tóth

Model structure and complexity selection remains a challenging problem in system identification, especially for parametric non-linear models.

TAG

Data-driven Modelling of Dynamical Systems Using Tree Adjoining Grammar and Genetic Programming

no code implementations5 Apr 2019 Dhruv Khandelwal, Maarten Schoukens, Roland Tóth

Based on the results achieved for the case studies, we critically analyse the performance of the proposed method.

Cannot find the paper you are looking for? You can Submit a new open access paper.