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Conception d'observateurs non linéaires par approche multimodèle : application au diagnostic

Abstract : The work carried out in this thesis concerns the design of robust nonlinear observers with model uncertainties as weIl as unknown inputs. The developed methods concern a class of a nonlinear systems represented by a multiple model. The stability conditions of the proposed observers are formulated using exclusively the second method of Lyapunov and its formulation in Linear Matrix Inequality (LMI) form. The synthesized observers can be grouped into two categories: The first one is based on explicitly eliminating the effect of the unknown inputs (disturbance of additive nature) in state estimation error. However, this approach is unpractical when the considered multiple model is subject to parametric uncertainty (disturbance of multiplicative nature). The second category attempts to handle the difficulties encountered previously. The underlying princip.le is to compensate the effects of the different disturbances. This is achieved by introducing the concept of sliding mode, which is robust against the model uncertainties, in the observer structure. The developed observers are used to implement sensor and actuator fault detection and isolation pro- cedure for the class of nonlinear systems represented by a multiple model. For this purpose, we have adapted and transposed the existing fault detection and isolation methods developed in the context of the linear models. The efficiency of the proposed methodology is verified through an interesting application of turbojet engine described by a multiple model.
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Submitted on : Thursday, March 29, 2018 - 12:35:46 PM
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  • HAL Id : tel-01750007, version 1



Abdelkader Akhenak. Conception d'observateurs non linéaires par approche multimodèle : application au diagnostic. Autre. Institut National Polytechnique de Lorraine, 2004. Français. ⟨NNT : 2004INPL114N⟩. ⟨tel-01750007⟩



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