Publications associées à Digital control

Data-Driven Control Synthesis using Koopman Operator: A Robust Approach

Alireza Karimi, Mert Eyuboglu, Nathan Russell Powell

This paper proposes a data-driven control design method for nonlinear systems that builds upon the Koopman operator framework. In particular, the Koopman operator is used to lift the nonlinear dynamics to a higher-dimensional space where the so-called obse ...

2024

Accurate and agile flight with winged drones

Valentin Wüest

Drones hold promise to assist in civilian tasks. To realize this application, future drones must operate within large cities, covering large distances while navigating within cluttered urban landscapes. The increased efficiency of winged drones over rotary ...

EPFL2024

Dynamic pulse scheduling in ASDEX Upgrade: Disruption avoidance and investigation of the H-Mode density limit

Federico Alberto Alfredo Felici, Alessandro Pau, Bernhard Sieglin

Operation of a tokamak device requires the coordinated operation of a multitude of systems. The sequence of operations during a discharge is both too complex and fast for human interaction. A common way of operation is a predefined sequence of operations w ...

2023

Machine Learning Methods for Robust Uncertainty Quantification and Controller Approximation

Emilio Maddalena

This thesis is situated at the crossroads between machine learning and control engineering. Our contributions are both theoretical, through proposing a new uncertainty quantification methodology in a kernelized context; and experimental, through investigat ...

EPFL2023

Fredholm transformation on Laplacian and rapid stabilization for the heat equation

Shengquan Xiang

We study the rapid stabilization of the heat equation on the 1-dimensional torus using the backstepping method with a Fredholm transformation. This classical framework allows us to present the backstepping method with Fredholm transformations for the Lapla ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Second-order adjoint-based sensitivity for hydrodynamic stability and control

Edouard Boujo

Adjoint-based sensitivity analysis is routinely used today to assess efficiently the effect of open-loop control on the linear stability properties of unstable flows. Sensitivity maps identify regions where small-amplitude control is the most effective, i. ...

Cambridge University Press2021

Nature of Crack Path Instabilities in Thin Sheets Cut by Blunt Objects

Iryna Sivak

Cutting a brittle thin sheet with a blunt object leaves an oscillating crack that seemingly violates the principle of local symmetry for fracture. We experimentally find that at a critical value of a well chosen control parameter the straight propagation i ...

AMER PHYSICAL SOC2020

The Role of the Control Framework for Continuous Teleoperation of a Brain-Machine Interface-Driven Mobile Robot

José del Rocio Millán Ruiz, Felix Christian Bauer, Luca Tonin

Despite the growing interest in brain-machine interface (BMI)-driven neuroprostheses, the translation of the BMI output into a suitable control signal for the robotic device is often neglected. In this article, we propose a novel control approach based on ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

The JET upgraded toroidal Alfven Eigenmode Diagnostic System

Ambrogio Fasoli, Duccio Testa, Patrick Blanchard

The Alfven Eigenmode Active Diagnostic system (AEAD) has undergone a major upgrade and redesign to provide a state-of-the-art excitation and real-time detection system for JET. The new system consists of individual 4 kW amplifiers allowing for increased cu ...

2019

Multi-Variable High-Frequency Input-Admittance of Grid-Connected Converters: Modeling, Validation and Implications on Stability

Drazen Dujic, Francisco Daniel Freijedo Fernández, Marc Ferrer Duran

Modern grids are facing a massive integration of power electronics devices, usually associated to instability issues. In order to assess the likelihood and severity of harmonic instability in the high frequency region, this work develops a multi-variable i ...

2019

Large‐Range HS‐AFM Imaging of DNA Self‐Assembly through In Situ Data‐Driven Control

Alireza Karimi, Georg Fantner, Maartje Martina Cornelia Bastings, Adrian Pascal Nievergelt, Christoph Manuel Kammer, Eva Eugene Kurisinkal, Charlène Cécile Geneviève Brillard

Understanding hierarchical self-assembly of biological structures requires real time measurement of the self-assembly process over a broad range of length- and timescales. The success of high-speed atomic force microscopy (HS-AFM) in imaging small scale mo ...

2019

Low-Complexity Optimization-Based Control: Design, Methods and Applications

Ivan Pejcic

Optimization-based controllers are advanced control systems whose mechanism of determining control inputs requires the solution of a mathematical optimization problem. In this thesis, several contributions related to the computational effort required for o ...

EPFL2019

Two-degrees-of-freedom (PID)-D-2 controller for precise nanopositioning in the presence of hardware-induced constant time delay

Andres San Millan Rodriguez

The fast and accurate tracking of periodic and arbitrary reference trajectories is the principal goal in many nanopositioning applications. Flexure-based piezoelectric stack driven nanopositioners are widely employed in applications where accurate mechanic ...

ELSEVIER SCIENCE INC2019

Frequency-Domain Control Design in Power Systems

Christoph Manuel Kammer

The scope of this thesis encompasses two main subjects: fixed-structure data-driven control design on one side, and control design in power systems on the other. The overall goal is to identify challenging and relevant problems in power systems, to express ...

EPFL2018

Decentralized and Distributed Transient Control for Microgrids

Alireza Karimi, Christoph Manuel Kammer

This paper treats the problem of primary and secondary control design in low-inertia power grids with mixed lines and a large amount of inverter-interfaced generation. A dynamic phasor model is developed that represents the electromagnetic and electromecha ...

Institute of Electrical and Electronics Engineers2019

Distributed digital real-time control system for the TCV tokamak and its applications

Olivier Sauter, Basil Duval, Stefano Coda, Timothy Goodman, Jean-Marc Moret, Federico Alberto Alfredo Felici, Cristian Galperti, Doohyun Kim, Himank Anand

A key feature of the new digital plasma control system installed on the TCV (Tokamak à Configuration Variable) tokamak is its possibility to rapidly design, test and deploy real-time algorithms. It accommodates hundreds of diagnostic inputs and actuator ou ...

IOP Publishing Ltd2017

Exploration of candidate fusion reactor regimes by real time control of tokamak plasma shape

Himank Anand

The potential of nuclear fusion to provide a practically inexhaustible source of energy has motivated scientists to work towards developing nuclear fusion tokamak power plants. Stable operation of a tokamak at high performance requires simultaneous treatme ...

EPFL2017

A Data-Driven Approach to Power Converter Control via Convex Optimization

Alireza Karimi, Achille Nicoletti, Michele Martino

A new model reference data-driven approach is presented for synthesizing controllers for the CERN power converter control system. This method uses the frequency re- sponse function (FRF) of a system in order to avoid the problem of unmodeled dynamics assoc ...

2017

A Nonlinear Adaptive Controller for Airborne Wind Energy Systems

Colin Neil Jones, Ioannis Lymperopoulos, Andrea Alessandretti, Sanket Sanjay Diwale

A nonlinear adaptive path following controller for a kite based airborne wind energy system is presented. For a given desired geometric path, we provide necessary conditions for closed-loop convergence of the kite to a tube centered around the desired path ...

2016

Continuous-time Model Predictive Control for Economic Optimization : Theory, Design, and Applications to Motion Control of Underactuated Vehicles

Andrea Alessandretti

This thesis addresses the design of optimization-based control laws for the case where convergence to a desired set-point, minimization of an arbitrary performance index, or a combination of the two, is the desired objective. The results are developed with ...

EPFL2016