ADAPTIVE CONTROL OF DC MOTOR WITHOUT IDENTIFICATION OF PARAMETERS

Parameter identification is a major problem in industrial environments where it might be difficult or even impossible in some situations. Moreover, non-measurable and unknown variations of system parameters can affect the performance of conventional proportional-integral (PI) controllers.  The concept of developing a controller that does not depend on the system parameters seems very interesting. Therefore, this paper deals with the experimental implementation of model reference adaptive control of a DC motor without identifying parameters. Adaptive control is considered an online solution to control a system without knowing system parameters since it can be adjusted automatically to maintain favorable tracking performance. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed control method

Contribution of the return of experience to security

International audienceThe development of risk project requires at first the census particularly of potential accidents list. This study is generally made during the risks Preliminary Hazard Analysis method. The collection of these potential accidents requires mainly, not only experts’ expertise of the field, but also Field Data Feedback. Up to Now, this crucial problem remains the archway key of the improvement of the system security level. Indeed, there is no explicit procedure to exploit systematically the results stemming from Field Data Feedback to elaborate out Preliminary Hazard Analysis. This article suggests a methodology allowing to exploit in a systematic way the Field Data Feedback in order to work out the Preliminary Hazard Analysis on one hand and take into account the potential accidents from the specification stage of the project on the other hand

Efficient harmony search optimization for preventive-maintenance-planning for nuclear power systems

This paper combines the universal generating function UGF with harmony search (HSO) meta-heuristic optimization method to solve a preventive maintenance (PM) problem for series-parallel system. In this work, we consider the situation where system and its components have several ranges of performance levels. Such systems are called multi-state systems (MSS). To enhance system availability or (reliability), possible schedule preventive maintenance actions are performed to equipments and affect strongly the effective age. The MSS measure is related to the ability of the system to satisfy the demand. The objective is to develop an algorithm to generate an optimal sequence of maintenance actions providing system working with the desired level of availability or (reliability) during its lifetime with minimal maintenance cost rate. To evaluate the MSS system availability, a fast method based on UGF is suggested. The harmony search approach can be applied as an optimization technique and adapted to this PM optimization problem

Efficient harmony search optimization for preventive-maintenance-planning for nuclear power systems

This paper combines the universal generating function UGF with harmony search (HSO) meta-heuristic optimization method to solve a preventive maintenance (PM) problem for series-parallel system. In this work, we consider the situation where system and its components have several ranges of performance levels. Such systems are called multi-state systems (MSS). To enhance system availability or (reliability), possible schedule preventive maintenance actions are performed to equipments and affect strongly the effective age. The MSS measure is related to the ability of the system to satisfy the demand. The objective is to develop an algorithm to generate an optimal sequence of maintenance actions providing system working with the desired level of availability or (reliability) during its lifetime with minimal maintenance cost rate. To evaluate the MSS system availability, a fast method based on UGF is suggested. The harmony search approach can be applied as an optimization technique and adapted to this PM optimization problem

Elaboration d'une table de commutation floue pour la commande d'un filtre actif de puissance

International audienceL'étude faite dans cet article concerne l'utilisation du concept de contrôle direct de puissance dans la commande d'un filtre actif parallèle. Cette stratégie est utilisée pour améliorer les performances du filtre actif de puissance en matière d'élimination d'harmonique et de compensation de puissance réactive. L'utilisation de la stratégie de contrôle direct de puissance engendre l'apparition d'ondulations au niveau des différentes grandeurs caractérisant le filtre actif de puissance, ce qui peut limiter ses performances de filtrage et de compensation. A cet effet on se propose, dans cet article, l'utilisation d'une méthode intelligente pour la sélection de la position du vecteur de tension, en remplaçant la table de commutation classique par un système à inférences floues. Les résultats de simulation numérique donnée à la fin de cet article montrent l'efficacité de la solution proposée

Elaboration d'une table de commutation floue pour la commande d'un filtre actif de puissance

International audienceL'étude faite dans cet article concerne l'utilisation du concept de contrôle direct de puissance dans la commande d'un filtre actif parallèle. Cette stratégie est utilisée pour améliorer les performances du filtre actif de puissance en matière d'élimination d'harmonique et de compensation de puissance réactive. L'utilisation de la stratégie de contrôle direct de puissance engendre l'apparition d'ondulations au niveau des différentes grandeurs caractérisant le filtre actif de puissance, ce qui peut limiter ses performances de filtrage et de compensation. A cet effet on se propose, dans cet article, l'utilisation d'une méthode intelligente pour la sélection de la position du vecteur de tension, en remplaçant la table de commutation classique par un système à inférences floues. Les résultats de simulation numérique donnée à la fin de cet article montrent l'efficacité de la solution proposée

Impact of antibiotic treatment for chronic endometritis on unexplained recurrent pregnancy loss

International audienc

Efficient harmony search optimization for preventive-maintenance-planning for nuclear power systems

This paper combines the universal generating function UGF with harmony search (HSO) meta-heuristic optimization method to solve a preventive maintenance (PM) problem for series-parallel system. In this work, we consider the situation where system and its components have several ranges of performance levels. Such systems are called multi-state systems (MSS). To enhance system availability or (reliability), possible schedule preventive maintenance actions are performed to equipments and affect strongly the effective age. The MSS measure is related to the ability of the system to satisfy the demand. The objective is to develop an algorithm to generate an optimal sequence of maintenance actions providing system working with the desired level of availability or (reliability) during its lifetime with minimal maintenance cost rate. To evaluate the MSS system availability, a fast method based on UGF is suggested. The harmony search approach can be applied as an optimization technique and adapted to this PM optimization problem