Publications related to System analysis

Liquid film instability of an internally coated horizontal tube

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière, Shahab Eghbali

We study numerically and theoretically the gravity-driven flow of a viscous liquid film coating the inner side of a horizontal cylindrical tube and surrounding a shear-free dynamically inert gaseous core. The liquid-gas interface is prone to the Rayleigh-P ...

AMER PHYSICAL SOC2023

Data-Driven Unknown-Input Observers and State Estimation

Giancarlo Ferrari Trecate, Mustafa Sahin Turan

Unknown-input observers (UIOs) allow for estimation of the states of an LTI system without knowledge of all inputs. In this letter, we provide a novel data-driven UIO based on behavioral system theory and the result known as Fundamental Lemma proposed by J ...

2022

Balancing high-speed rotors at low speed using optimized parametric excitation and tuned nonlinear feedback

Amit Yedidia Dolev

The paper presents an improved slow-speed mass balancing procedure capable of reducing high-speed related imbalance. Parametric excitation is used to project the small imbalance forces onto a chosen mode of vibration, corresponding to a high critical rotat ...

PERGAMON-ELSEVIER SCIENCE LTD2022

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

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

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

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

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

Alireza Karimi, Achille Nicoletti, Yuanming Zhu

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

Stochastic impulse control with regime-switching dynamics

Yaroslav Melnyk

Optimal product management problems with multiple product generations in continuous time lead to the consideration of dynamic optimal control problems that feature both intervention costs and partially controlled regime shifts. We therefore investigate and ...

Elsevier Science Bv2017

Fixed-structure Control of LTI Systems with Polytopic-type Uncertainty : Application to Inverter-interfaced Microgrids

Mahdieh Sadat Sad Abadi

This thesis focuses on the development of robust control solutions for linear time-invariant interconnected systems affected by polytopic-type uncertainty. The main issues involved in the control of such systems, e.g. sensor and actuator placement, control ...

EPFL2016

Interaction between counterpropagating Rossby waves and capillary waves in planar shear flows

François Gallaire, Luca Biancofiore

A counterintuitive destabilizing effect of the surface tension in planar wakes has been observed by Tammisola et al. ["Effect of surface tension on global modes of confined wake flows," Phys. Fluids 23, 014108 (2011)] and Biancofiore et al. ["Direct numeri ...

American Institute of Physics2015

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

Phase Analysis of the Stretching Cycles of the Head of Unsteady Gravity Currents Developing over Smooth and Rough Beds

Mário Jorge Rodrigues Pereira Da Franca, Helena Isabel Dos Santos Nogueira, Claudia Adduce

Gravity currents are buoyancy driven flows occurring spontaneously in nature or resulting from human intervention. Examples of gravity currents in the water are oceanic fronts, resulting from differences in temperature and salinity, and turbidity currents ...

Chengdu University Press2013

RST Controller Design by Convex Optimization Using Frequency-Domain Data

Alireza Karimi, Roland Longchamp, Gorka Galdos Sanz de Galdeano

A new robust fixed-order RST controller design approach by convex optimization is proposed in this paper. Only frequency-domain data are considered in the approach for linear time-invariant single-input single-output systems. It is shown that performance s ...

2011

Fixed-Order H-infinity Controller Design via Convex Optimization Using an Alternative to Youla Prameterization

Alireza Karimi, Hamid Khatibi

All H-infinity controllers of a SISO LTI system are parameterized thanks to the relation between Bounded Real Lemma and Positive Real Lemma and a new concept of strict positive realness of two transfer functions with the same Lyapunov matrix in the matrix ...

Institute of Electrical and Electronics Engineers2010

Data-driven tuning of linear parameter varying precompensators

Alireza Karimi, Mark Edward John Butcher

Methods for direct data-driven tuning of the parameters of precompensators for LPV systems are developed. Since the commutativity property is not always satisfied for LPV systems, previously proposed methods for LTI systems that use this property cannot be ...

Wiley-Blackwell2010

An Alternative to the Youla Parameterization for H infinity Controller Design

Alireza Karimi, Hamid Khatibi

All H infinity controllers of a SISO LTI system are parameterized thanks to the relation between the Bounded Real Lemma and the Positive Real Lemma. This new parameterization shares the features of Youla parameterization, namely the convexity of H infinity ...

2009

System identification with missing data via nuclear norm regularization

Colin Neil Jones

The application of nuclear norm regularization to system identification was recently shown to be a useful method for identifying low order linear models. In this paper, we consider nuclear norm regularization for identification of LTI systems with missing ...

2009

Preferential estimation

Levente Bodizs

State estimation is a necessary component of advanced monitoring and control techniques, since these techniques often require information that is too expensive or impossible to obtain from direct measurements. The objective of estimation is the reconstruct ...

EPFL2008

Data-driven Precompensator Tuning for Linear Parameter Varying Systems

Alireza Karimi, Roland Longchamp, Mark Edward John Butcher

Methods for direct data-driven tuning of the parameters of precompensators for LPV systems are developed. Since the commutativity property is not always satisfied for LPV systems, previously proposed methods for LTI systems that use this property cannot be ...

IEEE2008