Publications related to Time-variant system

Frequency domain data-driven robust and optimal control

The goal of this thesis is to propose pragmatic solutions to real challenges faced in the industry. The scope of this thesis encompasses two subjects: frequency-based structured controller synthesis for linear time-invariant (LTI) systems on one side, and ...

EPFL2024

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

Alireza Karimi, Vaibhav Gupta, Elias Sebastian Klauser

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

Neural System Level Synthesis: Learning over All Stabilizing Policies for Nonlinear Systems

Giancarlo Ferrari Trecate, Luca Furieri, Clara Lucía Galimberti

We address the problem of designing stabilizing control policies for nonlinear systems in discrete-time, while minimizing an arbitrary cost function. When the system is linear and the cost is convex, the System Level Synthesis (SLS) approach offers an effe ...

IEEE2022

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

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

Adaptive model predictive control for linear time varying MIMO systems

Vojislav Gligorovski

A robust, adaptive Model Predictive Control (MPC) approach for asymptotically stable, constrained linear time-varying (LTV) systems with multiple inputs and outputs is proposed. The approach consists of two-steps, carried out on-line with a receding horizo ...

2019

Electromagnetic Nonreciprocity

Karim Achouri, Christophe Caloz

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 design method for distributed luenberger observers

Colin Neil Jones, Francisco Fernandes Castro Rego

The paper addresses the problem of designing distributed observers for discrete linear time-invariant (LTI) systems with distributed sensor nodes subjected to bounded measurement noise. A solution is proposed in terms of a distributed LTI Luenberger observ ...

IEEE2018

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

High voltage metal oxide thin film transistors to drive arrays of dielectric elastomer actuators

Alexis Pierre Henri Marette

This thesis advances the field of high-voltage thin film transistors (HVTFTs) and dielectric elastomer actuators (DEAs) by demonstrating a strategy for low-voltage addressing of an array of high voltage soft actuators suspended on a flexible substrate. Fi ...

EPFL2018

Decentralized and distributed robust control invariance for constrained linear systems

Giancarlo Ferrari Trecate

In this paper we propose an efficient procedure to compute time-varying Robust Control Invariant (RCI) sets for large-scale systems arising from the interconnection of M Linear Time-Invariant (LTI) constrained subsystems. In particular, the associated stat ...

IEEE2017

Plug-and-play Voltage Stabilization in Inverter-interfaced Microgrids via a Robust Control Strategy

Alireza Karimi

This paper proposes a decentralized control strategy for the voltage regulation of islanded inverter-interfaced micro- grids. We show that an inverter-interfaced microgrid under plug- and-play (PnP) functionality of distributed generations (DGs) can be cas ...

Institute of Electrical and Electronics Engineers2017

Plug-and-Play Robust Voltage Control of DC Microgrids

Alireza Karimi

The purpose of this paper is to explore the appli- cability of linear time-invariant (LTI) dynamical systems with polytopic uncertainty for modeling and control of islanded DC microgrids under plug-and-play (PnP) functionality of distributed generations (D ...

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

Perimeter flow control in bi-modal urban road networks: A robust feedback control approach

Nikolaos Geroliminis, Nan Zheng, Konstantinos Ampountolas

n this paper, we integrate a three-dimensional Macroscopic Fundamental Diagram (3D-MFD) modelling for mixed bi-modal urban traffic in a control framework for congested urban regions. The 3D-MFD relates the accumulation of cars and buses and the outflow (or ...

IEEE2014

Learning Stable Non-Linear Dynamical Systems with Gaussian Mixture Models

Aude Billard, Seyed Mohammad Khansari Zadeh

This paper presents a method for learning discrete robot motions from a set of demonstrations. We model a motion as a nonlinear autonomous (i.e. time-invariant) Dynamical System (DS), and define sufficient conditions to ensure global asymptotic stability a ...

2011

Vector Control of Single-Phase Voltage-Source Converters Based on Fictive-Axis Emulation

Alfred Rufer, Behrooz Bahrani, Stephan Kenzelmann

This paper presents an alternative way for the current regulation of single-phase voltage-source dc-ac converters in direct-quadrature (dq) synchronous reference frames. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) on ...

Institute of Electrical and Electronics Engineers2011

Vector Control of Single-Phase Voltage Source Converters based on Fictive Axis Emulation

Alfred Rufer, Behrooz Bahrani, Stephan Kenzelmann

This paper presents an alternative way for controlling the current of single-phase voltage source dc-ac inverters in a dq synchronous reference frame. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) quantities allowing t ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

Model predictive control of linear periodic systems - a unified framework including control of multirate and multiplexed systems

Colin Neil Jones

State-feedback model predictive control (MPC) of discrete-time linear periodic systems with possibly time-dependent state and control input dimension is considered. States and inputs are subject to hard, mixed, polytopic constraints. It is described how di ...

IEEE2009