Robust tracking design for uncertain MIMO systems using proportional–integral controller of order v

AbstractThis paper provides a systematic method to design robust tracking controllers of reference signals with bounded derivatives of order ν for uncertain multi‐input multi‐output (MIMO) systems with bounded parametric uncertainties, in particular, of rational multi‐affine type, and/or in presence of disturbances with bounded derivatives of order ν. The proposed controllers have state‐feedback structures combined with proportional–integral regulators of order ν (PIν). Theoretical tools and systematic methodologies are provided to effectively design robust controllers for the considered systems, also in case of additional bounded nonlinearities and/or not directly measurable states. Applicability and efficiency of the proposed methods are validated through three examples: the first one is theoretical and useful to validate the proposed methodology, the second case study presents a metal‐cutting problem for an industrial robot, and the third example deals with a composite robot, such as a milling machine

Robust Observer Design for Takagi-Sugeno Fuzzy Systems with Mixed Neutral and Discrete Delays and Unknown Inputs

A robust observer design is proposed for Takagi-Sugeno fuzzy neutral models with unknown inputs. The model consists of a mixed neutral and discrete delay, and the disturbances are imposed on both state and output signals. Delay-dependent sufficient conditions for the design of an unknown input T-S observer with time delays are given in terms of linear matrix inequalities. Some relaxations are introduced by using intermediate variables. A numerical example is given to illustrate the effectiveness of the given results

On the stability analysis of a class of multiple models

Abstract This paper proposes a method to discuss the stability analysis of multiple models. The proposed stability analysis is based on the use of scalar Lyapunov functions and the properties of M-matrices. An example is included to illustrate the proposed method

Effect of phenolic compounds extracted from turmeric (Curcuma longa L.) and ginger (Zingiber officinale) on cutaneous wound healing in wistar rats

Turmeric and ginger, widely used rhizomes in culinary arts, have several beneficial biological activities, such as hypoglycemic, hepato-protective, antimicrobial, and antioxidant properties. This work investigated the effects of three phenolic extracts isolated from turmeric and ginger rhizomes on anti-inflammatory and healing properties using the solid–liquid extraction method. Wistar rats were used as a biological model. The anti-inflammatory activity was evaluated on induced edema in the rat’s hind paw using carrageenan (1%). Paw volume was measured at 0 min, 45 min, 3 h, and 5 h. Treatment with turmeric and ginger extracts, administered at a dose of 100 mg/kg, revealed a reduction in edema volume by 98.8%, 94.8%, and 98.3% using an aqueous extract of turmeric, ethanolic extract of turmeric, and methanolic extract of ginger, respectively. The healing activity parameters of induced burns on the rat’s dorsal region in nine groups (7 rats each) were monitored daily throughout the experiment’s duration. Results showed that the application of creams composed of petroleum jelly dispersing turmeric and ginger extracts to wounds at a dose of 100 mg/kg g induced complete healing after 19 days while the negative control was only 60% cured. On day 14, the aqueous, ethanolic, and methanolic turmeric extracts nearly resulted in complete tissue repair by 95.26%, 98.34%, and 87.39%, respectively. According to the chromatographic analysis (Sephadex G50 column), there is a variation in the molecular weight distribution of phenolic compounds (polymers, oligomers, and monomers) in the three studied extracts, which has a differential effect on the anti-inflammatory and wound healing activities of the extracts.info:eu-repo/semantics/publishedVersio

Stabilité et commande de systèmes décrits par des multimodèles : Approche LMI

Rapporteurs : Pierre BORNE (61 sec.) prof. à l'école centrale-Lille : LAIL Germain GARCIA (61 sec.) prof. à l'INSA-Toulouse : LAAS Examinateurs : Benoît BERGEON (61 sec.) prof. à l'université de Bordeaux I : LAP Jamal DAAFOUZ (61 sec.) Mcf. à l'INPL-Nancy : CRANThis thesis deals with the issue of stability and stabilisation of nonlinear systems in multiple model approach. Our study is exclusively based on the second Lyapunov method and its formulation in Linear Matrix Inequality (LMI) form. It carried out around two axes: the first one deals with the quadratic stability and the second treats the non quadratic case. In the quadratic case, we derive sufficient stability conditions by using the properties of M-matrices. The construction of multiple observers in the case of non measurable decision variables and also with unknown entries is then studied. A non linear output feedback control law is also proposed. Two techniques to synthesis this control law are proposed. The first one is based on a convex formulation. The second technique use the transformation of the non convex problem of synthesis into a cone complementarity problem. To reduce the conservativness of the quadratic method, two non quadratic types of Lyapunov function are considered : the polyquadratic Lyapunov function and the piecewise quadratic function. Using the S-procedure, the stability conditions are derived in LMI form. These results led to reduce considerably the conservatism of the quadratic method. They allow to consider interesting extensions to design state/output controller and multiple observer. The obtained conditions are bilinear in the variables of synthesis. LMI formulations under rank constraint or by using linearisation's algorithms are proposed.Cette thèse concerne l'analyse de la stabilité et la synthèse de lois de commande pour les multimodèles. La démarche proposée est exclusivement basée sur la deuxième méthode de Lyapunov et sa formulation en termes d'Inégalités Matricielles Linéaires (LMI). L'étude que nous avons menée est organisée autour de deux axes : le premier traite l'analyse de la stabilité par des fonctions de Lyapunov quadratiques, le deuxième fait appel aux fonctions de Lyapunov non quadratiques. Dans le volet consacré à la méthode quadratique, nous avons développé des conditions suffisantes de stabilité en nous appuyant sur les propriétés des M-matrices. La conception de multiobservateurs dans le cas de variables de décision non mesurables est abordée ainsi que celle de multiobservateurs à entrées inconnues. Une loi de commande statique non linéaire basée sur le retour de sortie est également proposée. Deux techniques de synthèse de cette loi de commande sont exposées. La première est basée sur une formulation convexe sous forme de LMI. La deuxième technique, quant à elle, est basée sur la transformation du problème (non convexe) de synthèse en un problème de complémentarité sur le cône. Pour réduire le pessimisme de la méthode quadratique, deux types de fonction de Lyapunov non quadratiques sont considérées : les fonctions dites polyquadratiques et les fonctions quadratiques par morceaux. En utilisant la procédure S, les conditions de stabilité obtenues sont formulées sous forme de LMI. Ces résultats ont abouti à réduire considérablement le conservatisme de la méthode quadratique et permettent d'envisager des extensions intéressantes concernant la commande par retour d'état ou de sortie ainsi que l'estimation d'état des multimodèles. Les conditions obtenues étant bilinéaires par rapport aux variables de synthèse, elles sont résolues en utilisant des algorithmes de linéarisation ou à l'aide de formulation LMI sous contrainte de rang