Publications associées à RST Controller Design by Convex Optimization Using Frequency-Domain Data

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

Data-driven IQC-Based Robust Control Design for Hybrid Micro-disturbance Isolation Platform

Alireza Karimi, Elias Sebastian Klauser, Vaibhav Gupta

A novel approach for robust controller synthesis, which models uncertainty as an elliptical set, is proposed in the paper. Given a set of frequency response functions of linear time-invariant (LTI) multiple-input multiple-output (MIMO) systems, the approac ...

IEEE2023

Achieving Optimal Performance With Data-Driven Frequency-Based Control Synthesis Methods

Alireza Karimi, Philippe Louis Schuchert

Frequency Response Function (FRF)-based control synthesis methods for Linear Time-Invariant (LTI) systems have been widely used in control theory and industry. Recently, there has been renewed interest in these methods, employing numerical optimization too ...

Ieee-Inst Electrical Electronics Engineers Inc2023

Fast ion generation with ICRF waves and beams in the Wendelstein 7-X stellarator

Mike Machielsen

The largest operating stellarator, Wendelstein 7-X, is of the quasi-isodynamic type. For this design to scale up to a fusion reactor, several criteria must be met, one of them being good fast ion confinement. The latter still has to be tested experimentall ...

EPFL2023

On Consensusability of Linear Interconnected Multi-Agent Systems and Simultaneous Stabilization

Giancarlo Ferrari Trecate, Mustafa Sahin Turan, Liang Xu

Consensusability of multi-agent systems (MASs) certifies the existence of a distributed controller capable of driving the states of each subsystem to a consensus value. We study the consensusability of linear interconnected MASs (LIMASs) where, as in sever ...

2021

Shortest-support multi-spline bases for generalized sampling

Michaël Unser, Shayan Aziznejad, Alireza Naderi, Alexis Marie Frederic Goujon

Generalized sampling consists in the recovery of a function f, from the samples of the responses of a collection of linear shift-invariant systems to the input f . The reconstructed function is typically a member of a finitely generated integer-shift invar ...

2021

Advanced methods for Brillouin based distributed optical fiber sensors

Simon Adrien Zaslawski

After more than thirty years of continuous research and development, the performances of conventional Brillouin based distributed optical fiber sensors (DOFS) are now peaking, as they are facing fundamental barriers that restrict the power of the light inj ...

EPFL2021

A Data-Driven Fault Location Algorithm Based on the Electromagnetic Time Reversal in Mismatched Media

Mario Paolone, Zhaoyang Wang, Zhe Chen

The classical electromagnetic time reversal (EMTR) fault location method in power systems can be time consuming, especially when a high location accuracy is desired. To cope with this issue, the concept of EMTR in mismatched media has recently been introdu ...

2021

A Note on BIBO Stability

Michaël Unser

The statements on the BIBO stability of continuoustime convolution systems found in engineering textbooks are often either too vague (because of lack of hypotheses) or mathematically incorrect. What is more troubling is that they usually exclude the identi ...

2020

A Vibrational Technique for in vitro Intraoperative Prosthesis Fixation Monitoring

Kamiar Aminian, Hooman Dejnabadi, Seyed Abdolmajid Yousefsani

Objective: In this paper, a new vibrational modal analysis technique was developed for intraoperative cementless prosthesis fixation evaluation upon hammering. Methods: An artificial bone (Sawbones)-prosthesis system was excited by sweeping of a sine signa ...

2020

Distributed state estimation for discrete-time linear time invariant systems: A survey

Colin Neil Jones, Francisco Fernandes Castro Rego

Motivated by the increasing availability and quality of miniaturized sensors, computers, and wireless communication devices arid given their enormous potential, the use of wireless sensor networks (WSN) has become widespread. Because in many applications o ...

2019

Robust H-infinity Controller Design Using Frequency-Domain Data via Convex Optimization

Alireza Karimi, Yuanming Zhu, Achille Nicoletti

A new robust controller design method that satisfies the H-infinity criterion is developed for linear time-invariant single-input single-output (SISO) systems. A data-driven approach is implemented in order to avoid the unmodeled dynamics associated with p ...

Wiley-Blackwell2018

Electromagnetic Nonreciprocity

Christophe Caloz, Karim Achouri

We aim at providing a global perspective on electromagnetic nonreciprocity and clarifying confusions that arose in recent developments of the field. We provide a general definition of nonreciprocity and classify nonreciprocal systems according to their lin ...

American Physical Society (APS)2018

A Data-Driven Frequency-Domain Approach for Robust Controller Design via Convex Optimization

Achille Nicoletti

The objective of this dissertation is to develop data-driven frequency-domain methods for designing robust controllers through the use of convex optimization algorithms. Many of today's industrial processes are becoming more complex, and modeling accurate ...

EPFL2018

Non-linear transfer function identification of pressure probes using Siren Disks

Jürg Alexander Schiffmann, Karim Magdi Zakaria Abdelrahman Shalash, Fatma Ceyhun Sahin

This article presents a Siren Disk proof of concept for the dynamic excitation of pressure probes, and a method to reconstruct distorted signals due to pneumatic channels. Constraints in sensor installation require placing a pressure transducer distant fro ...

2018

Fixed-structure H-2 controller design for polytopic systems via LMIs

Alireza Karimi, Arash Sadeghzadeh

In this paper a new approach for fixed-structure H2 controller design in terms of solutions to a set of linear matrix inequalities are given. Both discrete- and continuous-time single-input single-output (SISO) time- invariant systems are considered. Then ...

Wiley-Blackwell2015

From Fixed-Order Gain-Scheduling to Fixed-Structure LPV Controller Design

Zlatko Emedi

This thesis focuses on the development of some fixed-order controller design methods in the gain-scheduling/Linear Parameter Varying (LPV) framework. Gain-scheduled controllers designed using frequency-domain Single Input Single Output (SISO) models are co ...

EPFL2014

Fixed-order Controller Design for State Space Polytopic Systems by Convex Optimization

Alireza Karimi

In this paper, a new method for fixed-order controller design of systems with polytopic uncertainty in their state space representation is proposed. The approach uses the strictly positive realness (SPRness) of some transfer functions, as a tool to decoupl ...

2013

MPC of constrained discrete-time linear periodic systems — A framework for asynchronous control: Strong feasibility, stability and optimality via periodic invariance

Colin Neil Jones

State-feedback model predictive control (MPC) of discrete-time linear periodic systems with time-dependent state and input dimensions is considered. The states and inputs are subject to periodically time-dependent, hard, convex, polyhedral constraints. Fir ...

Elsevier2011

Fast O(1) Bilateral Filtering Using Trigonometric Range Kernels

Michaël Unser, Daniel Sage, Kunal Narayan Chaudhury

It is well known that spatial averaging can be realized (in space or frequency domain) using algorithms whose complexity does not scale with the size or shape of the filter. These fast algorithms are generally referred to as constant-time or O(1) algorithm ...

IEEE2011