Anis Messaoud

National Engineering School of Gabes · Génie Electrique Automatique

In this paper, an interval multiobserver is designed for nonlinear systems subject to unknown but bounded disturbances and measurement noises. The behavior of discrete nonlinear systems is described by an uncoupled multimodel. Linear Matrix Inequalities (LMIs) are formulated to study the stability of the proposed systems and to ensure the cooperati...

The present work focuses on the design of an interval multiobserver for nonlinear systems with internal and external disturbances. The structure of the developed interval multiobserver is based on a discrete uncoupled multimodel. The used multimodel is known for its flexibility in the modeling step, since the state variables of the partial models c...

The chattering phenomenon is one of the most pervasive problems in sliding mode control (SMC), especially for discrete time applications. In this paper, we propose a new discrete output feedback second order sliding mode control (DOF2SMC). The design of this controller is based on the Linear Matrix Inequalities (LMI) approach. Then, an adaptive swi...

The identification and the design of an accurate control are still an active researches of nonlinear systems subject to harmonic disturbances. In this paper, we propose two techniques to deal with nonlinear system identification and control problems. First, a new identification scheme based only on input/output measurements is proposed. In this sch...

An active sensor fault tolerant controller for nonlinear systems represented by a decoupled multimodel is proposed. Active fault tolerant control requires accurate fault estimation. Thus, to estimate both state variables and sensor faults, a discrete unknown input multiobserver, based on an augmented state multimodel, is designed. The multiobserver...

In this paper, a sensor fault detection and isolation scheme based on discrete unknown input multiobservers for a disturbed nonlinear systems is proposed. The proposed multiobservers are based on an uncoupled state multimodel. Sensor faults can be isolated using the generated structured residuals. Nevertheless, the presence of disturbances make the...

In the present paper, an unknown input multiobserver (UIMO) is designed for the state estimation of uncertain non-linear systems. A discrete decoupled state multimodel is exploited to describe the behavior of non-linear systems. A particular transformation of uncertainties to unknown inputs is considered. The LMI approach is used to establish the c...

This paper deals with the robustness enhancement of proportional Q-integral multiobserver in the case of non-stationary sinusoidal unknown inputs. The multimodel approach is proposed in order to overcome the complexity problems of nonlinear systems. The proposed multiobserver uses the multi-integral strategy in order to provide a simultaneous estim...

In this paper, we propose a new method for an optimal systematic determination of models' base for multimodel identification. This method is based on the neural classification of data set picked out on a considered nonlinear system. The obtained cluster centers are exploited to provide the weighting functions and to deduce the corresponding dispers...

In this paper, an online algorithm is proposed for the identification of unknown time-varying input delay in the case of discrete non-linear systems described by decoupled multimodel. This method relies on the minimization of a performance index based on the error between the real system and the partial internal models outputs. In addition, a decou...

In this paper, a robust multiobserver is proposed for the state estimation of discrete-time uncertain nonlinear systems with time-varying delay. The designed multiobserver is based on the decoupled multimodel approach. Unlike the classically used multimodel structures, the decoupled multimodel provides a flexibility of modelling. Indeed, the partia...

In the present work, we propose a supervised multimodel repetitive-predictive control scheme for discrete-time nonlinear systems in order to reject unknown non-stationary sinusoidal disturbances and to track reference trajectory. The nonlinear system is described by the decoupled state multimodel. Also, a non-stationary sinusoidal unknown input mul...

In this paper, a multi-rejector of periodic disturbances is proposed for discrete-time nonlinear systems represented by a decoupled state multimodel. We report a decoupled state multimodel repetitive-predictive control based on a supervised algorithm to ensure reference trajectory tracking and periodic disturbances rejection. Partial predictors ass...

The present paper deals with a decoupled multimodel predictive control based on multi-observer for the control of discrete-time nonlinear systems with time-varying delay. For each local model, a controller based on partial predictor/observer is synthesized. A switching algorithm is established to yield the adequate partial controller ensuring the c...

This paper deals with the robustness enhancement of proportional Q-integral multiobserver in the case of non-stationary sinusoidal unknown inputs. The multimodel approach is proposed in order to overcome the complexity problems of nonlinear systems. The proposed multiobserver uses the multi-integral strategy in order to provide a simultaneous estim...

This paper deals with a decoupled multimodel predictive control for discrete-time uncertain nonlinear systems. The control scheme is based on a multi-observer for the state estimation of uncertain nonlinear systems described by decoupled multimodel. A partial controller and observer is synthesized for each local model. In order to ensure the closed...

This paper deals with the design of robust non-stationary sinusoidal unknown inputmultiobserver for discrete-time nonlinear systems described by decoupled state multimodel. The particularity of this work resides in the fact that it provides a simultaneous state and non-stationary sinusoidal unknown inputs estimations. A new robust strategy allowing...

The multimodel approach is a powerful and practical tool to deal with analysis, modeling, observation, emulation and control of complex systems. In the modeling framework, we propose in this paper a new method for optimal systematic determination of models’ base for multimodel representation. This method is based on the classification of data set p...

In this work, a nonstationary sinusoidal unknown inputs multiobserver is proposed for discrete-time nonlinear systems represented by a decoupled multimodel. The existence conditions of this type of multiobserver will be addressed and a new strategy allowing the minimization of the impact of nonstationary sinusoidal unknown inputs on the state estim...

In this work, a second order asymptotic discrete sliding mode control with a fuzzy supervised discontinuous term is proposed. The on line variation of the discontinuous term amplitude enhances the convergence rapidity of the sliding function and reduces the chattering phenomenon. These improvements are shown by a numerical simulation and by a real...

The multimodel approach has become a major research topic during the last few decades and unlike many other advanced techniques, it has also been successfully applied in industry. This paper describes the application of a multimodel generalised predictive control (MGPC) based on a commutation algorithm to the problem of a semi-batch reactor control...

The multimodel approach is recently developed in order to resolve the problems of the increasing complexity of many industrial processes. In this paper we propose a multi- model generalized predictive control based on a commutation algorithm. This commutation is controlled by partial predictors associated to the local controllers. These predictors...

In this paper, we develop a direct adaptive generalized pre-dictive control based on performances index and we show the limits of this control law in the presence of a highly non stationary system. We present thereafter a method for validities estimation in the case of multi-model generalized predictive control (MGPC). This method is based on an on...