L'objet de ce mémoire concerne la simulation numérique des variateurs de vitesse pour machines synchrones à pôles saillants avec enroulements amortisseurs. L'étude comporte trois parties. Dans la première partie nous présentons la méthodologie de simulation et le générateur de programmes de simulation GASPE. Ensuite nous développons les modèles des...
Following the principles proposed by workers at Berkeley University, we have developed a version of the electrostatic micromotor based on the sacrificial layer method combined with oxidation of the rotor. In order to study the behaviour of this electrostatic micromotor, we have elaborated two softwares. The first, called EFCREL, is to simulate the ...
This paper deals with a new way of synthesis and modelling of electrostatic induction micromotors by means of duality rules from the magnetic induction machine. An electromechanical model based on this method is given. Then, a computational procedure based on a general lumped parameter model and an electric field calculation code, has been develope...
Absorbing boundary conditions are generally associated to long-range memory behaviors. In the case of the Euler-Bernoulli beam, they are naturally based on Abel-Volterra operators of order 1/2. Diffusive realizations of them are introduced and used for the construction of an original and efficient boundary dynamic feedback control.
The goal of this paper is to propose observer-based controllers, either in state-space form or in polynomial representation, for fractional differential systems. As for linear differential systems of integer order, polynomial representation will allow us to take advantage of the Youla parametrization in order to asymptotically reject some perturbat...
This paper presents a time-domain modeling for the sound pressure radiated by a xylophone and, more generally, by mallet percussion instruments such as the marimba and vibraphone, using finite difference methods. The time-domain model used for the one-dimensional (1-D) flexural vibrations of a nonuniform bar has been described in a previous paper b...
In the last decades, fractional differential equations have become popular among scientists in order to model various stable physical phenomena with anomalous decay, say that are not of exponential type. Moreover in discrete-time series analysis, so-called fractional ARMA models have been proposed in the literature in order to model stochastic proc...
Cet ouvrage consacre le travail d'une équipe d'ingénieurs et de chercheurs qur le thème de la commande robuste appliquée au pilotage d'engins dans les domaines aéronautiques, spatial, terrestre et naval. Il propose une synthèse des différentes approches de commande optimale et de leur pertinence à traiter les problèmes de robustesse. Les méthodes d...
The paper describes the design and implementation of a security architecture for a HLA/RTI prototype developed at ONERA/CERT. The major security objective is to protect the intellectual property of firms participating to a distributed interactive simulation. We describe the techniques used to implement the security services: controlled subscription...
Représentation et codage de l’architecture des plantes. Une plante est constituée d’entités ayant des types et des formes variés. L’organisation géométrique et topologique de ses entités définit « l’architecture de la plante ». Avant le début des années 70, la seule façon de représenter l’architecture des plantes était de faire des dessins botaniqu...
