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State Space Modelling
No full textMasterClassical control theory is intrinsically linked to the frequency domain and thes-plane. The main drawback of classical control theory is the diculty toapply it in Multi-Input Multi-Output (MIMO) systems. Rudolf Emil Kalman(Hungarian-born American, May 19, 1930 July 2, 2016) is one of the greatestprotagonist of modern control theory1. He has introduced the concept of stateas well as linear algebra and matrices in control theory. With this formalismsystems with multiple inputs and outputs could easily be treated
Semiclassical gravity in the de Broglie-Bohm theory and the double scale theory
No full textsoumis aux Annales de la Fondation Louis de BroglieWe present a semiclassical gravity in the framework of the double scale theory, a new interpretation of quantum mechanics which expands on the de Broglie-Bohm (dBB) theory. In this interpretation, any quantum system is associated with two wave functions, one external and one internal. The external wave function drives the center-of-mass, as in the dBB theory, and spreads with time. The internal wave function corresponds to the density of an extended particle. It remains confined in space and its average position corresponds to the center of mass of the particle. We define, for an N-body system, new semi-classical gravity equations called Einstein-de Broglie equations. The external wave function of each body depends only on the internal wave functions of the N−1 others. They are deduced from Einstein's semi-classical equation by using the internal wave functions instead of the usual wave function. If we restrict to the dBB interpretation, we find the Newton-de Broglie equations that Struyve and Laloë have recently proposed independently. We show that the Newton-de Broglie and Einstein-de Broglie equations converge to Newton's gravity when h → 0, which gives a theoretical validation
Panel Method Based Guidance for Fixed Wing Micro Aerial Vehicles
No full textInternational audienceIn this study, previously proposed panel method based guidance algorithm is tested in a high fidelity simulation environment and in real-life scenarios with a fixed wing mini unmanned aerial vehicle. Panel method is a numerical tool, borrowed from fluid dynamics domain, that can generate collision free, smooth paths in environments with arbitrarily shaped obstacles. It guarantees convergence to global minima with little computational load. Local vector field generated by the panel method is used to demonstrate a simple path-planning and guidance of the fixed wing micro aerial vehicle with hardware experiments. Experimental results suggest that the proposed algorithm can generate collision free paths for a fixed wing aircraft without violating the vehicle's limited flight envelope
MÉTHODE D'ÉMISSION DE SIGNAUX RADIO PAR UN RADAR EMBARQUÉ AU SEIN D'UN VÉHICULE, DISPOSITIF ET PROGRAMME D'ORDINATEUR CORRESPONDANTS
No full textData-driven multifidelity surrogate models for rocket engines injector design
No full textInternational audienceImproving the predictive capabilities of reduced-order models for the design of injector and chamber elements of rocket engines could greatly improve the quality of early rocket chamber designs. In the present work, we propose an innovative methodology that uses high-fidelity numerical simulations of turbulent reactive flows and artificial intelligence for the generation of surrogate models. The surrogate models that were generated and analyzed are deep learning networks trained on a dataset of 100 large eddy simulations of a single-shear coaxial injector chamber. The design of experiments was created considering three design parameters: chamber diameter, recess length, and oxidizer–fuel ratio. The paper presents the methodology developed for training and optimizing the data-driven models. Fully connected neural networks (FCNNs) and U-Nets were utilized as surrogate-modeling technology. Eventually, the surrogate models for the global quantity, average, and root mean square fields were used in order to analyze the impact of the length of the post’s recess on the performances obtained and the behavior of the flow.<br /
Metropolis II: Investigating the Future Shape of Air Traffic Control in Highly Dense Urban Airspace
No full textInternational audienceMetropolis II aims to provide insights in what is needed to enable high-density urban air operations. It does this by investigating the foundation for U-space U3/U4 services. The final goal is to provide a unified approach for strategic deconfliction, tactical deconfliction, and dynamic capacity management. Highly-dense operations in constrained urban airspace will likely require a degree of complexity that does not exist in modern-day air traffic management. The expected high traffic demand will require a shared use of the airspace instead of assigning exclusive use of blocks of the airspace to some flights. A unified approach for traffic management is needed because at high-densities, airspace design, flight planning, and separation management become increasingly interdependent. Metropolis II builds upon the results of the first Metropolis project. Three concepts with a varying degree of centralisation will be compared using simulations. (1) The centralised concept will take a global approach for separation management. (2) The decentralised concept aims to give the individual agents separation responsibility. (3) The hybrid concept tries to combine a centralised strategic planning agent with a robust tactical separation strategy
Sur la classification des structures statistiques
No full textA statistical manifold is often obtained from a statistical model, namely a parametrized family of probability laws such that the metric is the Fisher met- ric. Starting from this observation, Lauritzen and Amari asked the following question: is it possible to realize statistical manifolds as finite dimensional sta- tistical models? This problem has been answered positively by Hong Van Le, who uses the Nash and Gromov embedding theorems to construct an embedding of the initial statistical manifold in Eucludian space of large enough dimension. Our approach is based on global analysis, we construct a statistical model of the exponential family on a canonical foliation in a compact statistical manifold. Finding characteristic obstructions to the existence of structures is a particu- larly important question arising in mathematics. In this work, we give conditions for an orientable manifold to admit an almost contact structure(almost cosymplectic structure), almost contact metric structure, contact structure, contact metric structure, cosymplectic(symplectic mapping torus) structure. We show that different classical structures in differential geometry defined by differential forms arises from the gauge equation of two dual connections.Une variété statistique est souvent obtenue à partir d'un modèle statistique, à savoir une famille paramétrée de lois de probabilités telle que m´etrique en soit la métrique de Fisher. Partant de cette constatation, Lauritzen et Amari ont posé la question suivante: est-il possible de réaliser les variétés statistiques comme modèles statistiques de dimension finie ? Ce problème a reçu une réponse positive par Hong Van Le, qui utilise les deux théorèmes suivants pour construire un plongement de la variété statistique initiale dans un espace Euclidien de dimension suffisamment grand. Ce résultat montre que les variétés statistiques compacte de dimension finie sont réalisables comme modèles statistiques, mais ne donne pas de forme explicite. Dans notre approche, fondée sur l'analyse globale, nous construisons un modèle statistique de la famille exponentielle sur un feuilletage canonique. Le faisceau de solutions de l'équation hessienne sur une structure de jauge est un ingrédient clé pour comprendre certaines propriétés importantes d'un point de vue cohomologique. Dans notre travail, une représentation canonique du groupe de Lie associé par le troisième théorème de Lie à l'algèbre de Lie formée par les sections est introduite. Sur le feuilletage(singulier) qu'elle définit, une caractérisation des feuilles hyperboliques compactes est alors obtenue grâce a la nullité de la classe hessienne ou de la classe radiante de la représentation affine canonique du groupe de Lie dans son algèbre de Lie . Nous concluons alors que ces feuilles sont dotées d'une structure de modèle statistique grâce a des manipulations de la géométrie de Koszul. Il est fréquent de se poser la question de l'existence d'une structure particulière sur une variété différentielle. Dans ce chapitre, on tentera de répondre au problème suivant: Soit M une variété différentiable orientable de dimension impaire donné. Existe-t-il sur M une structure presque cosymplectique (presque de contact), une structure métrique presque de contact, une structure de contact, une structure métrique de contact, une structure quasi-contact (2-calibrée ou encore structure presque cosymplectique contact), une structure cosymplectique et une structure cokählerienne ? Nous montrons que différente structures classique en géométrie différentielle définies au moyen de formes différentielles proviennent de l'équation de jauge de deux connexions duales
A Reverse Design Framework for Modifiable-off-the-Shelf Embedded Systems: Application to Open-Source Autopilots
No full textInternational audienceThe development of real-time embedded systems is usually preceded by an important design phase to ensure that functional and behavioural constraints are met. However, the modification of some systems, especially Unmanned Air Vehicles that need to be frequently customised, is typically done in an ad-hoc way. Indeed, the design information may not be available, which may affect the proper functioning of the system. This paper aims to propose a framework helping reverseengineering a Modifiable Off-The-Shelf (MOTS) embedded system in order to be able to ease its modification. In other words, our objective is to point out where modifications have to happen, and allow smooth use of third-party analysis and/or architecture exploration tools to reanalyse non-functional properties (safety, performances, etc.) regarding the customisation. This framework extracts functional-chains from the source code and represents them visually as a model-based design by using model-driven engineering settings
Degraded States of Engagement in Air Traffic Control
No full textInternational audienceSafety studies have identified attention as a recurring cause of incidents and accidents in air traffic control. However, little is known of the precise attentional states that lead to degraded ATC performance. Therefore, we surveyed 150 French en route air traffic controllers on the causes of and impacts on perceived cooperation, safety, and performance of seven degraded attentional states from the literature: task-related and task-unrelated mind wandering, mental overload, inattentional deafness and blindness, attentional entropy, and perseveration. Our findings indicated that task-related and task-unrelated mind wandering were the most prevalent but had the least impact on perceived safety. Conversely, inattentional blindness and attentional entropy were less reported but were considered a significant safety concern, while inattentional deafness affected cooperation. Most states were experienced in workload levels consistent with the literature. However, no other factor such as shift work was identified as a cause of these states. Overall, these findings suggest that “attention” is not a specific enough subject for ATC, as attentional issues can occur in various conditions and have different impacts. As far as safety is concerned, inattentional blindness should be the prime target for further research. Neuroergonomics in particular could help develop dynamic countermeasures to mitigate its impact