Delay system identification applied to the longitudinal flight of an aircraft through a vertical gust

International audienceThis paper deals with modelling and identification of aircraft dynamic entering a vertical gust. The identification approach initiated in (Fliess 2003) falls under a prospect for identification from tests carried out in the Flight Analysis Laboratory of the DCSD of ONERA in Lille. The plane is considered into various elements which consist in the fuselage, the wing and the tail. The model incorporates delays linked to the aircraft passage through the atmospheric turbulence

Delay system identification applied to the longitudinal flight of an aircraft through a vertical gust

International audienceThis paper deals with modelling and identification of aircraft dynamic entering a vertical gust. The identification approach initiated in (Fliess 2003) falls under a prospect for identification from tests carried out in the Flight Analysis Laboratory of the DCSD of ONERA in Lille. The plane is considered into various elements which consist in the fuselage, the wing and the tail. The model incorporates delays linked to the aircraft passage through the atmospheric turbulence

Modélisation et identification de comportements de l'avion en vol turbulent par modèles à retards

This study relates to the mathematical representation of the behaviour of the aircraft in atmospheric turbulence as well as the identification of the dynamics induced by the gust. The approach falls under a prospect for identification from tests carried out in the Flight Analysis Laboratory of the DCSD of ONERA in Lille. To achieve this, the plane is considered into variouselements which consist in the fuselage, the wing and the tail. The obtained model incorporates unsteady effects, modelled via Küssner functions, and clearly clarified delays.Results in simulation confronting our model with recent work on modelling (Jauberthie's PhD thesis) highlight the fact that these phenomena have to be taken into account in the modelling. The comparison with experimental data shows that the tendencies observed during the tests are confirmed for our model.The algebraic identification method initiated by Fliess and Sira-Ramirez in 2003 was extended to time delay systems. This technique based on the distributional framework allows to identify some delays and parameters of our model.Cette étude porte sur la représentation mathématique du comportement de l'avion dans la turbulence atmosphérique ainsi que sur l'identification de la dynamique induite par la rafale de vent. La démarche suivie s'inscrit dans une perspective d'identification à partir d'essais réalisés dans le Laboratoire d'Analyse du Vol du DCSD de l'ONERA à Lille. Pour cela, l'avion estdécomposé en différents éléments que sont le fuselage, l'aile et l'empennage. Le modèle obtenu incorpore les effets instationnaires modélisés par l'intermédiaire de fonctions de Küssner et des retards clairement explicités.Des résultats en simulations confrontant le modèle développé à de récents travaux de modélisation (thèse de Carine Jauberthie à l'ONERA) mettent en évidence l'apport de la prise en compte de ces phénomènes dans la modélisation. La comparaison avec les essais expérimentaux montre que les tendances observées dans la réalité se confirment pour notre modèle.Une méthode d'identification algébrique initiée par Fliess et Sira-Ramirez en 2003 a été étendue aux systèmes à retards. Cette technique basée sur le formalisme des distributions permet d'identifier certains retards et paramètres de notre modèle

Langage, corps chez Ludwig Binswanger

Comme il y a, à côté du corps physique, un corps vécu, une chair dont le caractère de relation transparaît jusque dans la reformulation du concept de subjectivité, il y a à côté du langage comme simple outil de signification, une langue qui, habitée pour elle-même, donne accès au silence. Selon Ludwig Binswanger, bien que comportant chacun en son sein trace de leur commune origine nostrale-, un fragment de l autre -, langage et chair ne sauraient être rabattus l un sur l autre. Transformer le langage en un organisme vivant qui ne serait que vivant, ayant par conséquent abdiqué son être-pour-la-mort, c est se condamner à une production de sens interminable, celle du discours du schizophrène par exemple. Chair et langage sont les deux pans d un même abîme, celui qui s ouvre dans la béance d un espace perdu. Cet espace est inhabitable, car tendu par des directions de sens opposées qui doivent être parcourues simultanément cependant que l immobilité est non moins insupportable puisqu elle est la négation même de la vie (catatonie, mutisme). Il faut donc un élan accompagné d un d une vitesse permettant de parcourir incessamment cet espace, de l abolir tout en le laissant subsister. Mais comment déterminer cette vitesse, en fixer le tempo, sans remonter à la dissonance originelle qui a mué l espace en distance ? Retrouver le tempo à partir d une dissonance : tel est le défit commun du fou, du psychiatre et du philosophe, défi dont la reconnaissance amorce seule, selon Binswanger, la guérison de l homme.As ther is, besides the physical body, a lived body, a flesh whose relation character is visible up to the reformulation of the subjectivity concept, there is, besides the language, as mere instrument of the meaning, a language which, inhabited for itself, give access to the silence. According to Ludwig Biswanger, although language and flesh contain each of them an element of the other - trace of their common origin : the We - they should not be fold back on each other. To transform the language into an organism - which would only be alive, so would have renounced to its being-for-the-death - is tout lock ourselves in the endless production of significance, as for example the discourse of schizophrenics. Flesh and Language are the two pieces of the same abyss, the one which opens in the gap of a lost space. This space is uninhabitable, because stretched by opposed meaning s directions which must be simultaneaously covered while immobility is not less unbearable since it is the very negation of life (catatonia, muteness). Thus, a spring, a speed are needed to continuously cover this space, to abolish it while it subsists. But how to determine this speed, to define the tempo, without going back to the very origin of the dissonance which changed space into distance ? That is the common challenge of the mad, the psychiatrist and the philosopher. Only the recognition of this challenge opens, according to Binswanger, the cure of the human being.PARIS4-BU Serpente (751052129) / SudocSudocFranceF

Modélisation et identification de comportements de l'avion en vol turbulent par modèles à retards

LILLE1-BU (590092102) / SudocVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF

Delay system identification applied to the longitudinal flight of an aircraft through a vertical gust

International audienceThis paper deals with modelling and identification of aircraft dynamic entering a vertical gust. The identification approach initiated in (Fliess 2003) falls under a prospect for identification from tests carried out in the Flight Analysis Laboratory of the DCSD of ONERA in Lille. The plane is considered into various elements which consist in the fuselage, the wing and the tail. The model incorporates delays linked to the aircraft passage through the atmospheric turbulence

Improving animal health and welfare in the transition of livestock farming systems: towards social acceptability and sustainability

The need to integrate more clearly societal expectations on livestock farming has led the authors of this article to consider that livestock farming systems must be redesigned to position health and welfare at the heart of their objectives. This article proposes a vision of the advances in knowledge required at different scales to contribute to this transformation. After defining health and welfare of animals, the article emphasizes the need to consider health in a broader perspective, to deepen the question of positive emotional experiences regarding welfare, and raises the question of how to assess these two elements on farms. The positive interactions between health and welfare are presented. Some possible tensions between them are also discussed, in particular when improving welfare by providing a more stimulating and richer environment such as access to outdoor increases the risk of infectious diseases. Jointly improving health and welfare of animals poses a number of questions at various scales, from the animal level to the production chain. At the animal level, the authors highlight the need to explore: the long-term links between better welfare and physiological balance, the role of microbiota, the psycho-neuro-endocrine mechanisms linking positive mental state and health, and the trade-off between the physiological functions of production, reproduction and immunity. At the farm level, in addition to studying the relationships at the group level between welfare, health and production, the paper supports the idea of co-constructing innovative systems with breeders, as well as analyzing the cost, acceptability and impact of improved systems on their working conditions and well-being. At the production chain or territory levels, various questions are raised. These include: studying the best strategies to improve animal health and welfare while preserving economic viability, the labelling of products and the consumers’ willingness to pay, the consequences of heterogeneity in animal traits on the processing of animal products, and the spatial distribution of livestock farming and the organization of the production and value chain. At the level of the citizen and consumer, one of the challenges is to better inter-relate sanitary and health perspectives on the one hand, and welfare concerns on the other hand. There is also a need to improve citizens' knowledge on livestock farming, and to develop more intense and constructive exchanges between breeders, the livestock industry and citizens. These difficult issues plead for interdisciplinary and transdisciplinary research involving various scientific disciplines and the different stakeholders, including public policy makers through participatory research