Alexandre Seuret - Academia.edu (original) (raw)

Papers by Alexandre Seuret

Je tiensà remercier très vivement Monsieur Jean-Pierre Richard et Monsieur Michel Dambrine de m'a... more Je tiensà remercier très vivement Monsieur Jean-Pierre Richard et Monsieur Michel Dambrine de m'avoir accepté dans leuréquipe, de leur enthousiasme envers mon travail, de leur disponibilité. Les judicieux conseils qu'ils m'ont prodigués tout au long de ces trois années de thèse m'ont permis de progresser dans mesétudes et d'achever ce travail dans les meilleures conditions.

2009 European Control Conference (ECC), 2009

arXiv: Optimization and Control, 2019

This paper deals with the exponential stability of a drilling pipe controlled by a PI controller.... more This paper deals with the exponential stability of a drilling pipe controlled by a PI controller. The model used leads to a coupled ODE / PDE and is consequently of infinite dimension. Using recent advances in time-delay systems, we derive a new Lyapunov functional based on an state extension made up of projections of the Riemann coordinates. Two cases will be considered. First, we will provide an exponential stability result expressed using the LMI framework. This result is dedicated to a linear version of the torsional dynamic. On a second hand, the nonlinear terms in the initial model, that generates the well-known stick-slip phenomenon is captured through a new stability theorem. Numerical simulations show the effectiveness of the method and that the stick-slip oscillations cannot be weaken using a PI controller.

Journal of the Franklin Institute, 2021

This paper addresses the design of a sampled-data model predictive control (MPC) strategy for lin... more This paper addresses the design of a sampled-data model predictive control (MPC) strategy for linear parameter-varying (LPV) systems. A continuous-time prediction model, which takes into account that the samples are not necessarily periodic and that plant parameters continuously vary with time, is considered. Moreover, it is explicitly assumed that the value of the parameters used to compute the optimal control sequence is measured only at the sampling instants. The MPC approach proposed by Kothare et al. [1], where the basic idea consists in solving an infinite horizon guaranteed cost control problem at each sampling time using linear matrix inequalities (LMI) based formulations, is adopted. In this context, conditions for computing a sampled-data stabilizing LPV control law that provides a guaranteed cost for a quadratic performance criterion under input saturation are derived. These conditions are obtained from a parameter-dependent looped-functional and a parameter-dependent generalized sector condition. A strategy that consists in solving convex optimization problems in a receding horizon policy is therefore proposed. It is shown that the proposed strategy guarantees the feasibility of the optimization problem at each step and leads to the asymptotic stability of the origin. The conservatism reduction provided by the proposed results, with respect to similar ones in the literature, is illustrated through numerical examples.

Nonlinear Analysis: Hybrid Systems, 2018

The paper deals with the stability analysis of time-delay reset control systems, for which the re... more The paper deals with the stability analysis of time-delay reset control systems, for which the resetting law is assumed to satisfy a time-dependent condition. A stability analysis of the closed-loop system is performed based on an appropriate sampled-data system. New linear matrix inequality (LMI) conditions are proposed to ensure the exponential stability of the closed-loop resulting of the connection of a plant with a proportional and integral controller together with a reset integrator (PI+RI).

IFAC-PapersOnLine, 2017

This paper deals with the exponential stabilization of a time-delay system with an average of the... more This paper deals with the exponential stabilization of a time-delay system with an average of the state as the output. A general stability theorem with a guaranteed exponential decay-rate based on a Wirtinger-based inequality is provided. Variations of this theorem for synthesis of a controller or for an observer-based control is derived. Some numerical comparisons are proposed with existing theorems of the literature and comparable results are obtained but with an extension to stabilization.

Journal of the Franklin Institute, 2017

Integral inequalities for quadratic functions play an important role in the derivation of delay-d... more Integral inequalities for quadratic functions play an important role in the derivation of delay-dependent stability criteria for linear time-delay systems. Based on the Jensen inequality, a reciprocally convex combination approach was introduced in [17] for deriving delaydependent stability criterion, which achieves the same upper bound of the time-varying delay as the one on the use of the Moon et al.'s inequality. Recently, a new inequality called Wirtinger-based inequality that encompasses the Jensen inequality was proposed in [20] for the stability analysis of time-delay systems. In this paper, it is revealed that the reciprocally convex combination approach is effective only with the use of Jensen inequality. When the Jensen inequality is replaced by Wirtinger-based inequality, the Moon et al.'s inequality together with convex analysis can lead to less conservative stability conditions than the reciprocally convex combination inequality. Moreover, we prove that the feasibility of an LMI condition derived by the Moon et al.'s inequality as well as convex analysis implies the feasibility of an LMI condition induced by the reciprocally convex combination inequality. Finally, the efficiency of the methods is demonstrated by some numerical examples, even though the corresponding system with zero-delay as well as the system without the delayed term are not stable.

Automatica, 2017

This article investigates the asymptotic stability of impulsive delay dynamical systems (IDDS) by... more This article investigates the asymptotic stability of impulsive delay dynamical systems (IDDS) by using the Lyapunov-Krasovskii method and looped-functionals. The proposed conditions reduce the conservatism of the results found in the literature by allowing the functionals to grow during both the continuous dynamics and the discrete dynamics. Sufficient conditions for asymptotic stability in the form of linear matrix inequalities (LMI) are provided for the case of impulsive delay dynamical systems with linear and time-invariant (LTI) base systems (non-impulsive actions). Several numerical examples illustrate the effectiveness of the method.

IEEE Transactions on Automatic Control, 2017

This paper aims at constructing and analyzing an efficient framework for the leader-following con... more This paper aims at constructing and analyzing an efficient framework for the leader-following consensus protocol in multi-agent systems (MASs). We propose two novel consensus protocols weighted by calculating the betweenness and eigenvector centralities for agent and link which are determined by the interconnection structure of MASs. The concepts of centrality were introduced in the field of social science. Ultimately, the use of the proposed protocols can be described with regard to not only the number of each agent's neighbors, which was utilized in the existing works, but also more information about agents through considering two such centralities. By utilizing the Lyapunov method and some mathematical techniques, the leader-following guaranteed cost consensus conditions for MASs with the proposed protocols and sampleddata will be established in terms of linear matrix inequalities (LMIs). Based on the result of consensus criteria, two new protocol design methods which utilize the betweenness and eigenvector centralities will be proposed. Finally, some simulation results are given to illustrate the advantages of the proposed protocols in point of the robustness on sampling interval and the transient consensus performance.

Low-Complexity Controllers for Time-Delay Systems, 2014

ABSTRACT This paper considers the stability analysis of time-varying delay systems. We develop a ... more ABSTRACT This paper considers the stability analysis of time-varying delay systems. We develop a new integral inequality which is proved to encompasses the celebrated Jensen's inequality. These technical tools allow to construct simple Lyapunov-Krasovskii functionals very efficient in practice. Notice that our procedure is coupled with the use of the reciprocal convexity result in order to reduce the conservatism induced by the LMIs optimisation setup. The effectiveness of the proposed results is illustrated by some classical examples from the literature.

Systems & Control Letters, 2015

Assessing stability of time-delay systems based on the Lyapunov-Krasovskii functionals has been t... more Assessing stability of time-delay systems based on the Lyapunov-Krasovskii functionals has been the subject of many contributions. Most of the results are based, first, on the design of more and more involved class of functionals and, finally, on the use of the famous Jensen's inequality. In contrast with this design process, the present paper aims at providing a generic set of integral inequalities which are asymptotically non conservative and then to design functionals driven by these inequalities. The resulting set of stability conditions forms a hierarchy of LMI which is competitive with the most efficient existing methods (delay-partitioning, discretization and sum of squares), in terms of conservatism and of complexity. Finally, some examples show the efficiency of the method.

Lecture Notes in Control and Information Sciences, 2009

IFAC Proceedings Volumes, 2009

A novel method based on Lyapunov-Krasovskii functionals for the stability analysis of linear syst... more A novel method based on Lyapunov-Krasovskii functionals for the stability analysis of linear systems with constant is introduced. The Lyapunov-Krasovskii functionals are provided using polynomial parameters. Stability conditions are derived in the form of linear matrix inequalities. Examples show that these computationally tractable conditions can give tighter stability results than the ones in the literature.

This presentation addresses stability issues of sampled data controllers. Considering a continuou... more This presentation addresses stability issues of sampled data controllers. Considering a continuoustime linear plant and a linear discrete-time dynamic output feedback control law designed from a classical periodic sampling paradigm, the main goal is to assess the effects of aperiodic sampling on the closed-loop stability. This aperiodic sampling models for instance the communication delays and package losses through a network and induces an hybrid behavior for the system. In addition, the effects of control signal saturation on the stability and the maximal admissible sampling interval are also taken into account. In this context, based on the use of a looped functional, linear matrix inequalities (LMI) are derived to ensure the global asymptotic stability of the origin for the aperiodic sampled-data closed-loop system, provided a bound on the maximal sampling interval is given. An optimization problem in order to evaluate the maximal admissible value for the interval between two sampling instants is then associated to the LMI conditions.

Systems & Control Letters, 2012

A new functional-based approach is developed for the stability analysis of linear impulsive syste... more A new functional-based approach is developed for the stability analysis of linear impulsive systems. The new method, which introduces looped-functionals, considers non-monotonic Lyapunov functions and leads to LMIs conditions devoid of exponential terms. This allows one to easily formulate dwell-times results, for both certain and uncertain systems. It is also shown that this approach may be applied to a wider class of impulsive systems than existing methods. Some examples, notably on sampled-data systems, illustrate the efficiency of the approach.

International Journal of Systems Science, 2011

A method is proposed for stabilization, using static state feedback, of systems subject to time-v... more A method is proposed for stabilization, using static state feedback, of systems subject to time-varying delays in both the states and their derivatives (i.e., neutral systems), in the presence of saturating actuators. Delay-dependent conditions are given to determine stabilizing state-feedback controllers with large domain of attraction, expressed as linear matrix inequalities, readily implementable using available numerical tools and with tuning parameters that make possible to select the most adequate solution. These conditions are derived by using a Lyapunov-Krasovskii functional on the vertices of the polytopic description of the actuator saturations. Numerical examples demonstrate the effectiveness of the proposed technique.

IEEE Transactions on Automatic Control, 2009

Automatica, 2013

In the last decade, the Jensen inequality has been intensively used in the context of time-delay ... more In the last decade, the Jensen inequality has been intensively used in the context of time-delay or sampled-data systems since it is an appropriate tool to derive tractable stability conditions expressed in terms linear matrix inequalities (LMI). However, it is also well-known that this inequality introduces an undesirable conservatism in the stability conditions and looking at the literature, reducing this gap is a relevant issue and always an open problem. In this paper, we propose an alternative inequality based on the Fourier Theory, more precisely on the Wirtinger inequalities. It is shown that this resulting inequality encompasses the Jensen one and also leads to tractable LMI conditions. In order to illustrate the potential gain of employing this new inequality with respect to the Jensen one, two applications on time-delay and sampled-data stability analysis are provided.

The problem statement is presented in section 1.6. An overview of control and scheduling co-desig... more The problem statement is presented in section 1.6. An overview of control and scheduling co-design is finally presented in Section 1.7. • Chapter 2 starts with the presentation of a robust weakened real-time system, in which the motivation for the need of a more flexible framework is proposed. In section 2.2 the notion of weakened real-time framework is presented as well as the different possible scheduling scenarii that can be associated with it. As the introduction of this new idea, on weakening the real-time constraints, has risen new problems, the theoretical basis to solve these new problems are discussed in section 2.4.2. In section 2.4.1 and it is shown how to handle these different problems. Then, section 2.4.2 shows how to apply the presented tools with systems having sampled-data inputs because such models are used all along this thesis to model A conclusion is given in chapter 4, where a summary of the thesis and new perspectives of research are presented.