Ahmed El Hajjaji

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This paper addresses robust observer based H<sub>infin</sub> control problem for Takagi-Sugeno fuzzy systems with time-varying norm bounded uncertainties. Sufficient relaxed conditions for synthesis of a fuzzy observer and a fuzzy controller for T-S fuzzy systems are derived in terms of a set of linear matrix inequalities (LMIs). In comparison with the(More)
This paper presents a robust method for estimation the lateral velocity of vehicle. The proposed observer describes a simple structure that contains a sliding mode term which turns out to be robust against output noises and parameters variations as well as sustained disturbances The given nonlinear model of the vehicle is then represented by an uncertain(More)
This paper focuses on the control of diesel HCCI engine air path. We propose a control strategy based on Recursive Model Free Controller (RMFC). This kind of controller is simple to design and it needs only the outputs of the system. On other hand, in order to estimate the state variables, an observer is used and its convergence is performed by using(More)
Environmental issues and respect for the European Union's objectives for green house emissions reduction, has required an improved in the sophistication of control strategies. This article focuses on the control of the air path diesel engine. Most studies consider the following control setup: intake pressure and intake air flow are controlled using EGR and(More)
This paper addresses the modeling and control of the air path system of diesel engines. We propose robust control for the diesel engine equipped with Exhaust Gas Recirculation (EGR) and Variable Geometry Turbocharger (VGT) systems. The goal is to control carefully the air flow for a diesel engine to reduce emissions of pollutant particles and fuel(More)
This paper deals with the problem of delay-dependent stability and stabilization of Takagi-Sugeno (T-S) fuzzy systems with a time-varying delay. A new method which brings three great advantages for the T-S delay-dependent stabilization problem is developed. The first one is that this method is less conservative than other existing ones. The second one is(More)
An Adaptive Sliding Mode Control (ASMC) for a class of nonlinear Multi Input Multi Output (MIMO) systems is presented in this paper. In order to reduce the chattering phenomenon without deteriorating the tracking performance, the discontinuous term of the classical sliding mode law is substituted with an adaptive Proportional Derivative (PD) term. The(More)
In this paper an approach for detecting impending rollover is proposed. The method includes an algorithm based on Takagi-Sugeno (TS) fuzzy observer to prevent rollover of the vehicle when road adhesion conditions change. To design such observer, we take into account that roll rate can be measured easily by sensor, but roll angle is not measured. The(More)
This paper deals with the problem of the state estimation and the sensor faults detection for discrete time nonlinear systems described by Takagi-Sugeno (TS) fuzzy models with unmeasurable premise variables. Indeed, a TS observer is synthesized, in descriptor form, to estimate both the system states and the sensor faults simultaneously. The idea of the(More)
A vehicle dynamics control system (NCS) has been developed in this study for improving vehicle yaw rate dynamics under unreliable communication links with packet dropouts, and network-induced delay which are two typical network constraints of unreliable transmission. The NCS system consists of a fuzzy H<sub>&#x221E;</sub> static output feedback controller.(More)