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

Neuro-Fuzzy fault detection method for photovoltaic systems

Abstract In this work we present a faults detection method for photovoltaic systems (PVS). This method is based on the calculation of sets of parameters of a PV module in different operating conditions, by means of a Neuro-Fuzzy approach. The PV system status is determined by evaluation and comparison of norms based on the aforementioned parameters, with threshold values. This intelligent system developed in Matlab&Simulink environment, consists on the study of the crucial information that the six parameters in normal and faulty condition contain. They are calculated using the I-V curves and synthesized by "hybrid" models. Results show that the diagnosis system is able to discern between normal and faulty operation conditions and with the same defective existence of noise and disturbances

Comparison of LMI Solvers for Robust Control of a DC-DC Boost Converter

This work deals with a robust Fault-Tolerant Control (FTC) design for a class of uncertain systems. Fault resilience is associated with a robustness bound generated by a sufficient Linear Matrix Inequality (LMI) condition for static state feedback stabilization. This design control approach is based on solving an optimization problem expressed in terms of LMI with three different programming solvers which are mincx (Matlab), lmisolver (Scilab) and cvxopt (Python). Numerical validations were carried out, first on an academic model, then on the model of a PV energy conversion system connected to a DC-DC boost converter. Then, a robustness analysis for fault resilience associated with a control law gains, obtained using the three solvers, was realized to investigate the best performance. This approach was finally validated on an experimental test bench

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

Self-consistent random phase approximation in the Schutte-Da-Providencia fermion-boson model

Théori

Vehicle State and Parameters Estimation Using Sliding Mode Observer

Feb 2007, Buenos Aires, Argentina. pp.43--48, 2007International audienceIn this paper, we present a Robust Sliding Mode Observer for systems with unknown Inputs. The system considered is a vehicle model with unknown inputs that represent the attributes of the road (slope and banking of the road). This parameters affect the vehicle dynamic performance and behavior properties. Thus for vehicles and road safety analysis, it is necessary to take into account this parameters. However, slope and banking of road are difficult to measure directly. In this work we deal with a simple model of vehicle and we develop a method to observe slope and banking of the road

Vehicle State and Parameters Estimation Using Sliding Mode Observer

Feb 2007, Buenos Aires, Argentina. pp.43--48, 2007International audienceIn this paper, we present a Robust Sliding Mode Observer for systems with unknown Inputs. The system considered is a vehicle model with unknown inputs that represent the attributes of the road (slope and banking of the road). This parameters affect the vehicle dynamic performance and behavior properties. Thus for vehicles and road safety analysis, it is necessary to take into account this parameters. However, slope and banking of road are difficult to measure directly. In this work we deal with a simple model of vehicle and we develop a method to observe slope and banking of the road

Low-Cost Sensor for Vehicle Speed Based on Sliding Mode Observer

International audience— This paper presents a new robust observer methodology based on sliding mode for estimation of vehicle velocity. The paper addresses the design and implementation issues of such observer which is based on the measurement by a standard sensor in many of the new cars. This is the encoders which are mounted in the ABS system. They provide a low angular resolution position measurement. The estimate has been validated experimentally using an instrumented vehicle by different sensors. The actual results show effectiveness and robustness of the proposed metho

Estimation de la dynamique du véhicule en interaction avec son environnement

Le cadre général du travail de recherche est l'application des outils de l'automatique non linéaire (observateurs par modes de glissemen commande robuste, ... ) et des méthodes pour le diagnostic en vue de l'amélioration de la Sécurité des véhicules et de Routes. Des études d'accidentologies ont montré le rôle de l'infrastructure dans la majorité des accidents. L'objectif est donc d'utiliser le plus d'informations possible sur l'environnement, pour mieux piloter et évaluer le comportement (nominal) d'un véhicule dans sa trajectoire. La difficulté et le coût des mesures de forces de contact pneu chaussé nous ont motivé pour développer des observateurs non linéaires et robustes pour estimer les informations (forces de contact, adhérence, dérive, raideurs) utile pour caractériser la tenue de route du véhicule. Ensuite nous avons mis au point une nouvel/e technique d'estimation avec des observateurs en cascade pour déduire les vitesses puis les accélérations angulaires des roues à partir des codeurs de l'ABS grâce à un observateur robuste par modes glissants d'ordre supérieur. Cette technique permet d'estimer ensuite, la raideur longitudinale des pneus et le rayon effectif. On peut aussi reconstituer l'adhérence et la dérive qui représentent des caractéristiques importantes de la route et du roulement du véhicule respectivement Aprés cela nous avons proposé des observateurs robustes à entrée inconnue permettant d'estimer les attributs de la route (profil, pente et dévers). Ces derniers sont utiles pour l'aide à la conduite. Enfin, nous présentons en dernier une méthode de conception de systèmes permettant de détecter des défauts dans la dynamique d'un véhicule en roulemeThe general framework of the research is the application of the nonlinear control tools (sliding mode observers, robust control ... ) and methods for diagnostics in order to improve the security of the vehicle. Motivation of our work is due to the fact that the infrastructure is involved the majority of accidents. the was born, which uses as more as possible the environmental information's in order to study the comportment of the vehicle in its trajectory. The difficulties and the high costs of the sensors, to measure contact forces belween wheel and the ground were an important motivation for design of non linear and robust observers. Then, a new technique for the estimation with cascaded observers was developed to dedu the angular velocities and accelerations of wheels by use of the ABS encoders. This method al/ows us to estimate the longitudinal stiffness of each tire and its effective radius. The adherence also can be reconstructed. Robust observers with unknown inputs are proposed to estimate the road features (profile, slope and inclination angle), which are used to assist the driving. Final/y, we present a method for detecting faults in the dynamics of the vehicle. We have considered only Iwo types of faults: Faults in the suspension system Variation of pressure in tire.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF