Flow control using optical sensors

Created by W.Langdon from gp-bibliography.bib Revision:1.4333

  title =        "Flow control using optical sensors",
  titletranslation = "Contr{\^o}le d'ecoulement par capteurs optiques",
  author =       "Nicolas Gautier",
  school =       "Pierre and Marie Curie University - Paris VI",
  year =         "2014",
  month =        oct # "~08",
  address =      "Paris",
  keywords =     "genetic algorithms, genetic programming, flow control,
                 graphic processor unit, contr{\^o}le d'ecoulement, GPU,
                 boucle fermee, marche descendante, experimental, [PHYS,
                 MECA, mefl] physics [physics]/mechanics
                 [physics]/mechanics of the fluids [physics, class-ph]",
  publisher =    "HAL CCSD",
  bibsource =    "OAI-PMH server at api.archives-ouvertes.fr",
  contributor =  "Physique et mecanique des milieux heterogenes and
                 Jean-Luc Aider",
  identifier =   "NNT : 2014PA066640; tel-01150428",
  language =     "en",
  oai =          "oai:HAL:tel-01150428v1",
  URL =          "https://tel.archives-ouvertes.fr/tel-01150428",
  URL =          "https://tel.archives-ouvertes.fr/tel-01150428/document",
  URL =          "https://tel.archives-ouvertes.fr/tel-01150428/file/2014PA066640.pdf",
  size =         "211 pages",
  abstract =     "Flow control using optical sensors is experimentally
                 investigated. Real-time computation of flow velocity
                 fields is implemented. This novel approach featuring a
                 camera for acquisition and a graphic processor unit
                 (GPU) for processing is presented and detailed. Its
                 validity with regards to speed and precision is
                 investigated. A comprehensive guide to software and
                 hardware optimisation is given. We demonstrate that
                 online computation of velocity fields is not only
                 achievable but offers advantages over traditional
                 particle image velocimetry (PIV) setups. It shows great
                 promise not only for flow control but for parametric
                 studies and prototyping also.

                 A hydrodynamic channel is used in all experiments,
                 featuring a backward facing step for separated flow
                 control. Jets are used to provide actuation. A
                 comprehensive parametric study is effected to determine
                 the effects of upstream jet injection. It is shown
                 upstream injection can be very effective at reducing
                 recirculation, corroborating results from the
  abstract =     "Both open and closed loop control methods are
                 investigated using this setup. Basic control is
                 introduced to ascertain the effectiveness of this
                 optical setup. The recirculation region created in the
                 backward-facing step flow is computed in the vertical
                 symmetry plane and the horizontal plane. We show that
                 the size of this region can be successfully manipulated
                 through set-point adaptive control and gradient based
                 methods.A physically driven control approach is
                 introduced. Previous works have shown successful
                 reduction recirculation reduction can be achieved by
                 periodic actuation at the natural Kelvin-Helmholtz
                 frequency of the shear layer.A method based on vortex
                 detection is introduced to determine this frequency,
                 which is used in a closed loop to ensure the flow is
                 always adequately actuated. Thus showing how
                 recirculation reduction can be achieved through simple
                 and elegant means using optical sensors.

                 Next a feed-forward approach based on ARMAX models is
                 implemented. It was successfully used in simulations to
                 prevent amplification of upstream disturbances by the
                 backward-facing step shear layer. We show how such an
                 approach can be successful in an experimental

                 Higher Reynolds number flows exhibit non-linear
                 behaviour which can be difficult to model in a
                 satisfactory manner thus a new approach was attempted
                 dubbed machine learning control and based on genetic
                 programming. A number of random control laws are
                 implemented and rated according to a given cost
                 function. The laws that perform best are bred, mutated
                 or copied to yield a second generation. The process
                 carries on iteratively until cost is minimised. This
                 approach can give surprising insights into effective
                 control laws.",
  abstract =     "Le contr{\^o}le d'ecoulement en utilisant des capteurs
                 optiques est etudie dans un contexte experimental. Le
                 calcul de champs de vitesses en temps reel en utilisant
                 une camera pour l'acquisition et une carte graphique
                 pour le calcul est detaille. La validite de l'approche
                 en terme de rapidite et de precision est etudiee. Un
                 guide complet pour l'optimisation logicielle et
                 materielle est donne. Nous demontrons que le calcul
                 dynamique de champs de vitesse est non seulement
                 possible mais plus facile {\`a} gerer que l'utilisation
                 d'un appareillage (PIV) classique. Un canal
                 hydrodynamique est utilise pour toutes les experiences.
                 Celui-ci comporte une marche descendante pour le
                 contr{\^o}le d' ecoulements decolles. Les actionneurs
                 sont des jets. Dans le cas de la marche descendante une
                 etude parametrique approfondie est faite pour qualifier
                 les effets d'une injection en amont des jets, celle-ci
                 etant traditionnellement .......",
  annote =       "oai:HAL:tel-01150428v1 Physique et mecanique des
                 milieux heterogenes (PMMH) ; CNRS - Universite Paris
                 Diderot - Paris 7 (UP7) - ESPCI ParisTech - Universite
                 Pierre et Marie Curie - Paris 6 (UPMC); Universite
                 Pierre et Marie Curie - Paris VI, English. ",

Genetic Programming entries for Nicolas Gautier