generalized multiple delay-dependent H∞, functional observer design for nonlinear system

Producción CientíficaFunctional observers are the major alternative to many practical estimation problems where full-order observers cannot be used. This paper introduces a generalized approach to design H∞ functional observers for a class of Lipschitz nonlinear systems with multiple time delays. Moreover, the considered system extends from previously published work in that it presents nonlinearity, multiple delay and external disturbance. Their main findings come from the development of a generalized augmented Lyapunov function that uses both the extended reciprocal convex combination and the Wirtinger inequality. The stability of the observer is therefore guaranteed by an LMI optimization problem. Finally, the steps of the design procedure were condensed and proffered for the two numerical examples to test the recommended design approach

Design of robust control for uncertain fuzzy quadruple-tank systems with time-varying delays

Producción CientíficaThe robust H∞ observer-based control design is addressed here for non-linear Takagi-Sugeno (T-S) fuzzy systems with time-varying delays, subject to uncertainties and external disturbances. This is motivated by the quadruple-tank with time delay control problem. The observer design methodology is based on constructing an appropriate Lyapunov–Krasovskii functional (LKF) for an augmented system formed from the original and the delayed states. The bilinear terms are transferred to the linear matrix inequalities, thanks to a change of variables which can be solved in one step. Furthermore, by employing the L2 performance index, the adverse effects of persistent bounded disturbances is largely avoided. The proposed method has the advantage of relating the controller and Lyapunov function to both the original and delayed states. Then, the controller and observer gains are obtained simultaneously by solving these inequalities with off-the-shelf software (Yalmip/MATLAB toolbox). Finally, an application to a simulated quadruple-tank system with time delay is carried out to demonstrate the benefits of the proposed technique, showing a compromise between controller simplicity and robustness that outperforms previous approaches.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Observation de systèmes à entrées inconnues, applications à la dynamique automobile

Advanced driver assistance systems for active safety need the dynamic state of the vehicle to build effective automatic control strategies. This thesis deals with the use of unknown input observers to estimate variables related to the vehicle state and its environment. After presenting different models of vehicle, different unknown input state observers of linear and nonlinear systems are defined to estimate variables of the vehicle dynamics.Les systèmes actifs d'aide à la conduite des véhicules automobiles ont besoin d'informations sur l'état du véhicule pour construire des stratégies de contrôle efficaces. L'objectif de cette thèse est de développer des observateurs à entrées inconnues qui permettent d'estimer différentes variables liées à l'état du véhicule et de son environnement. Après avoir présenté différentes modélisations du véhicule, différents observateurs d'état à entrées inconnues de systèmes linéaires et non linéaires sont exposés afin d'estimer des variables explicatives de la dynamique du véhicule

Redéfinition de la supervision dynamique d'une automobile à partir de nouveaux capteurs

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Evaluation of Torque Observer in Automotive Context

International audienceThis paper describes how it is possible to estimate online the individual torque at each wheel of an automotive vehicle by using an unknown input observer together with a simple longitudinal 4 wheels model. The necessary measurements are the usual otation speed of each wheel plus the vertical load at the center of each wheel. By doing this, this study anticipates the affordability of a new generation of wheel bearing with embedded measurements of transmitted forces. Successful simulated experimentations of the method are shown as well as its present limits

H infini dynamic observer design for discrete-time linear systems with time varying delays based on generalized reciprocally convex matrix inequality

International audienceIn this work, we have studied the problem of designing dynamic observers (HDO) for discrete-time linear systems (DTLS) with time-varying delay (TVD) and disturbance. By designing an augmented Lyapunov-Krasovskii functional (LKF) with double summation terms using the Generalized reciprocally convex matrix inequality (GRCMI), as well as the Jensen-based inequality (JBI) and the Wirtinger-based inequality (WBI) that derive new less conservative time-dependent conditions. The resulting algebraic conditions form a set of linear matrix inequalities (LMIs) which can be solved by the LMI or YALMIP toolboxes. Furthermore, the observer under consideration has more degrees of freedom to be estimated, and is known as a generalized observer, where the proportional and proportional-integral observers are particular cases. Finally, two examples are given to demonstrate the validity and effectiveness of the findings

Torques and Vehicle State: an Automotive Application of Unknown Inputs Observer

International audienceThis paper describes how it is possible to estimate online the individual torques at each wheel of an automotivevehicle by using an unknown input observer together with avehicle model including the sprung mass pitch motion. The necessary measurements are the usual rotation speed plus the vertical load at the center of each wheel. This assumption anticipates the affordability of a new generation of wheel bearings with embedded measurements of transmitted forces. Successful simulated experimentations of the method are shown using a realistic simulator

Redefining Automotive Supervision Using new sensor technology

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