Nancy Research Center for Automatic Control

Nancy, France

Nancy Research Center for Automatic Control

Nancy, France
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Laroche E.,French National Center for Scientific Research | Boutayeb M.,Nancy Research Center for Automatic Control
IEEE Transactions on Energy Conversion | Year: 2010

This paper presents an original method for estimation of the induction motor parameters, including iron loss, with measurements in the sinusoidal steady-state mode. Based on a change of parameter yielding a model that is linear with respect to the new set of parameters, this method allows parameter estimation with low computation cost and without being concerned by local minima problems. This method is evaluated and compared with two other methods from the literature, which are also based on sinusoidal steady-state measurements: a standard method based on two elementary tests and a method where parameters are estimated through minimization of a nonconvex distance criterion with a nonlinear programming algorithm. For the considered methods, sensitivities to measurement and modeling errors are evaluated, emphasizing the performances of the originalmethod. Experimental results, obtained on a setup of 1.5kWrated power, are provided. © 2009 IEEE.


Chadli M.,University of Picardie Jules Verne | Darouach M.,Nancy Research Center for Automatic Control
Automatica | Year: 2012

This paper concerns the bounded real lemma for discrete-time descriptor systems. A new formulation of the bounded real lemma for these systems is given. It extends the recent results presented in Zhang, Xia, and Shi (2008) and gives necessary and sufficient conditions in strict LMI (linear matrix inequality) which is more suitable for the control design than those presented in Zhang, Xia, and Shi (2008). An application to the H∞ control design is given. A numerical example is presented to show the applicability of our approach. © 2011 Elsevier Ltd. All rights reserved.


Postoyan R.,Nancy Research Center for Automatic Control | Nesic D.,University of Melbourne
Automatica | Year: 2012

We consider a general class of nonlinear reduced-order observers and show that the global asymptotic convergence of the observation error in the absence of network-induced constraints is maintained for the emulated observer semiglobally and practically (with respect to the maximum allowable transmission interval) when system measurements are sent through a communication channel. Networks governed by a Lyapunov uniformly globally asymptotically stable protocol are investigated. Our results can be used to synthesize various observers for networked control systems for a range of network configurations, as we illustrate it by considering classes of immersion and invariance observers which include the circle-criterion observers. © 2012 Elsevier Ltd. All rights reserved.


Aberkane S.,Nancy Research Center for Automatic Control
Systems and Control Letters | Year: 2011

This paper deals with the problem of stochastic stability analysis and control synthesis of a class of Markovian jump linear systems (MJLS) with time-varying transition probabilities (TPs) in the discrete-time domain. The time-varying character is considered to be in a polytopic sense. The approach followed in this note is based on the use of a parameter dependent stochastic Lyapunov function. We give a stability condition in terms of a linear matrix inequality (LMI) feasibility problem. The obtained results are illustrated in a numerical example. © 2010 Elsevier B.V.


Boukhobza T.,Nancy Research Center for Automatic Control | Hamelin F.,Nancy Research Center for Automatic Control
Automatica | Year: 2011

This paper deals with the state and input right-hand side observability and the sensor location problem to ensure this property for structured linear systems in the descriptor form. The proposed method is based on a graph-theoretic approach. It is applicable to a large class of descriptor systems including regular and nonregular systems even if they are underdetermined, overdetermined or square. After defining a bipartite graph which represents such systems, we deduce some graphic necessary and sufficient conditions to achieve the right-hand side observability of the state and the input. Next, we propose a sensor placement procedure to recover this property. More precisely, we provide the minimal number of the sensors required and either their pertinent location or a necessary and sufficient condition to check if a given sensor configuration is adequate or not to ensure state and input right-hand side observability. Our approach uses algorithms with polynomial complexity orders and assumes only the knowledge of the system's structure and so is suited for large scale systems. © 2011 Elsevier Ltd. All rights reserved.


Boukhobza T.,Nancy Research Center for Automatic Control | Hamelin F.,Nancy Research Center for Automatic Control
Automatica | Year: 2011

This paper deals with the observability of the discrete mode, the internal state and the input of switching structured linear systems with unknown input. The proposed method, based on a graph-theoretic approach, assumes only the knowledge of the system's structure. We express, in graphical terms, necessary and sufficient conditions for the generic observability of the discrete mode, the continuous internal state and the input of a switching structured linear system. These conditions can be implemented by classical graph theory algorithms based on finding particular paths and cycles in a digraph. © 2010 Elsevier Ltd. All rights reserved.


Darouach M.,Nancy Research Center for Automatic Control
Systems and Control Letters | Year: 2012

This paper is concerned with the design of functional observers for linear time-invariant descriptor systems. Contrary to the functional observers considered for the standard systems in Darouach [8], where the order of these observers is equal to the dimension r of the functional to be estimated, in this paper the order can be of dimension different of that of this functional. When this order is equal to the dimension of the functional and the system is in a standard form, the presented design method becomes that of Darouach [8]. It also generalizes the existing results for descriptor systems. The approach is based on the new definition of partial impulse observability. Sufficient conditions for the existence and stability of these observers are given. Continuous time and discrete time systems are considered. Two numerical examples are given to illustrate our approach. © 2011 Elsevier B.V. All rights reserved.


Postoyan R.,Nancy Research Center for Automatic Control | Nesic D.,University of Melbourne
IEEE Transactions on Automatic Control | Year: 2012

This technical note proposes a framework for the observer design for networked control systems (NCS) affected by disturbances, via an emulation-like approach. The proposed model formulation allows us to consider various static and dynamic time-scheduling protocols, in-network processing implementations and encompasses sampled-data systems as a particular case. Provided that the continuous-time observer is robust to the measurement errors (in an appropriate sense) we derive bounds on the maximum allowable transmission interval that ensure the convergence of the observation errors under network-induced communication constraints. The stability analysis is trajectory-based and utilizes small-gain arguments. A number of observers can be combined and used within our approach to obtain estimators for NCS. © 2012 IEEE.


Darouach M.,Nancy Research Center for Automatic Control
IEEE Transactions on Automatic Control | Year: 2014

This technical note is devoted to the observers and observer-based control for linear descriptor systems. First, the complete proof of necessary and sufficient conditions for the existence of Luenberger observers for an arbitrary order is given, then the existence conditions for the controller based on these observers are presented in the LMI formulation. The design approach is simple and based on the new study of the constrained generalized Sylvester equations. It unifies all the observers and observer-based controllers of different orders. A numerical example is presented to illustrate our approach. © 2013 IEEE.


Jain T.,Nancy Research Center for Automatic Control
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2011

A behavioral theoretical explanation of active fault tolerant control (FTC) problem is proposed in this note. Precisely, we present the concept of canonical controller and unfalsified control in behavioral context. The synergy of two control concepts re-configures the controller such that the system is tolerant to unknown faults. The main feature of the resulting FTC system is that it does not utilize any model-based fault detection and isolation procedure on-line. Therefore, it relies solely on the time-valued trajectories generated by the unknown plant in the closed-loop environment. In our approach to FTC, these trajectories formulate the control specifications that characterize certain desired behavior. Consequently, the controller re-designing process commence when this desired behavior is not satisfied. © 2011 IFAC.

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