Institut de Recherche de l’École navale (IRENAV)http://hdl.handle.net/10985/66572024-03-29T15:05:00Z2024-03-29T15:05:00ZSpatial models for context-aware indoor navigation systems: A surveyAFYOUNI, ImadCLARAMUNT, ChristopheRAY, Cyrilhttp://hdl.handle.net/10985/66952024-03-13T13:31:43Z2012-01-01T00:00:00ZSpatial models for context-aware indoor navigation systems: A survey
AFYOUNI, Imad; CLARAMUNT, Christophe; RAY, Cyril
This paper surveys indoor spatial models developed for research fields ranging from mobile robot mapping, to indoor location-based services (LBS), and most recently to context-aware navigation services applied to indoor environments. Over the past few years, several studies have evaluated the potential of spatial models for robot navigation and ubiquitous computing. In this paper we take a slightly different perspective, considering not only the underlying properties of those spatial models, but also to which degree the notion of context can be taken into account when delivering services in indoor environments. Some preliminary recommendations for the development of indoor spatial models are introduced from a context-aware perspective. A taxonomy of models is then presented and assessed with the aim of providing a flexible spatial data model for navigation purposes, and by taking into account the context dimensions.
2012-01-01T00:00:00ZAFYOUNI, ImadCLARAMUNT, ChristopheRAY, CyrilThis paper surveys indoor spatial models developed for research fields ranging from mobile robot mapping, to indoor location-based services (LBS), and most recently to context-aware navigation services applied to indoor environments. Over the past few years, several studies have evaluated the potential of spatial models for robot navigation and ubiquitous computing. In this paper we take a slightly different perspective, considering not only the underlying properties of those spatial models, but also to which degree the notion of context can be taken into account when delivering services in indoor environments. Some preliminary recommendations for the development of indoor spatial models are introduced from a context-aware perspective. A taxonomy of models is then presented and assessed with the aim of providing a flexible spatial data model for navigation purposes, and by taking into account the context dimensions.Context-Aware Processing of Continuous Location-Dependent Queries in Indoor EnvironmentsAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, Cyrilhttp://hdl.handle.net/10985/96222024-03-13T13:31:43Z2013-01-01T00:00:00ZContext-Aware Processing of Continuous Location-Dependent Queries in Indoor Environments
AFYOUNI, Imad; ILARRI, Sergio; CLARAMUNT, Christophe; RAY, Cyril
Emerging and continuing advances in ambient systems and localization techniques have brought novel opportunities to develop context-aware navigation services in indoor environments. Diverse kinds of services delivered to the users can be provided by enabling real-time integration of contextual dimensions. In particular, continuous location-dependent queries can be considered as key elements for the development of different categories of context-aware services. However, most work on location-dependent query processing has been mainly oriented towards outdoor environments. This paper introduces a generic architecture for continuous location-dependent and navigationrelated queries in indoor environments. A multi-level model of space is designed by taking into account contextual information and the hierarchical layout of an indoor environment. The semantics of a query language for continuous location-dependent queries are introduced, along with some motivating sample queries.
This research was partially supported by a Short Term Scientific Mission performed by the first author at the University of Zaragoza and funded by the COST Action IC0903 on "Knowledge Discovery from Moving Objects" (MOVE project). We would also like to acknowledge the support of the CICYT project TIN2010-21387-C02-02 and DGAFSE.
2013-01-01T00:00:00ZAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, CyrilEmerging and continuing advances in ambient systems and localization techniques have brought novel opportunities to develop context-aware navigation services in indoor environments. Diverse kinds of services delivered to the users can be provided by enabling real-time integration of contextual dimensions. In particular, continuous location-dependent queries can be considered as key elements for the development of different categories of context-aware services. However, most work on location-dependent query processing has been mainly oriented towards outdoor environments. This paper introduces a generic architecture for continuous location-dependent and navigationrelated queries in indoor environments. A multi-level model of space is designed by taking into account contextual information and the hierarchical layout of an indoor environment. The semantics of a query language for continuous location-dependent queries are introduced, along with some motivating sample queries.A PostgreSQL Extension for Continuous Path and Range Queries in Indoor Mobile EnvironmentsAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, Cyrilhttp://hdl.handle.net/10985/93342024-03-13T13:31:43Z2014-01-01T00:00:00ZA PostgreSQL Extension for Continuous Path and Range Queries in Indoor Mobile Environments
AFYOUNI, Imad; ILARRI, Sergio; CLARAMUNT, Christophe; RAY, Cyril
Continuous location-dependent queries are key elements for the development of location-based and context aware services. While most works on location-dependent query processing have been mainly oriented towards outdoor environments, this paper develops an approach for the continuous processing of location-dependent queries over indoor moving objects. A prototype for handling those queries has been developed as an extension for the open source DBMS PostgreSQL. Several algorithms for the continuous processing of path searches and range queries applied to both static and moving objects are performed on top of a hierarchical and context-dependent data model. Experimental results have been conducted to report our findings.
2014-01-01T00:00:00ZAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, CyrilContinuous location-dependent queries are key elements for the development of location-based and context aware services. While most works on location-dependent query processing have been mainly oriented towards outdoor environments, this paper develops an approach for the continuous processing of location-dependent queries over indoor moving objects. A prototype for handling those queries has been developed as an extension for the open source DBMS PostgreSQL. Several algorithms for the continuous processing of path searches and range queries applied to both static and moving objects are performed on top of a hierarchical and context-dependent data model. Experimental results have been conducted to report our findings.Traitement continu des requêtes dépendantes de la localisation dans des environnements intérieursAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, Cyrilhttp://hdl.handle.net/10985/105242024-03-13T13:31:43Z2015-01-01T00:00:00ZTraitement continu des requêtes dépendantes de la localisation dans des environnements intérieurs
AFYOUNI, Imad; ILARRI, Sergio; CLARAMUNT, Christophe; RAY, Cyril
Cet article développe une représentation de données spatiales d’un environnement intérieur dit “indoor” qui tient compte des dimensions contextuelles centrées sur l’utilisateur et aborde les enjeux de gestion de données mobiles. Un modèle de données “indoor” hiérarchique et sensible au contexte est proposé. Cette conception hiérarchique favorise un traitement adaptatif et efficace des requêtes dépendantes de la localisation. Un langage de requêtes continues est développé et illustré par des exemples de requêtes. Cette approche de modélisation est complétée par le développement d’algorithmes de traitement continu des requêtes de recherche de chemin hiérarchique et des requêtes de zone sur des objets mobiles en “indoor”. Une étude expérimentale des solutions développées a été menée pour évaluer la performance et le passage à l’échelle à l’égard des propriétés intrinsèques des solutions proposées.
2015-01-01T00:00:00ZAFYOUNI, ImadILARRI, SergioCLARAMUNT, ChristopheRAY, CyrilCet article développe une représentation de données spatiales d’un environnement intérieur dit “indoor” qui tient compte des dimensions contextuelles centrées sur l’utilisateur et aborde les enjeux de gestion de données mobiles. Un modèle de données “indoor” hiérarchique et sensible au contexte est proposé. Cette conception hiérarchique favorise un traitement adaptatif et efficace des requêtes dépendantes de la localisation. Un langage de requêtes continues est développé et illustré par des exemples de requêtes. Cette approche de modélisation est complétée par le développement d’algorithmes de traitement continu des requêtes de recherche de chemin hiérarchique et des requêtes de zone sur des objets mobiles en “indoor”. Une étude expérimentale des solutions développées a été menée pour évaluer la performance et le passage à l’échelle à l’égard des propriétés intrinsèques des solutions proposées.Cavity induced vibration of flexible hydrofoilsAKCABAY, Deniz TolgaCHAE, Eun JungYOUNG, Yin LuDUCOIN, AntoineASTOLFI, Jacques Andrehttp://hdl.handle.net/10985/89922023-12-15T10:04:14Z2014-01-01T00:00:00ZCavity induced vibration of flexible hydrofoils
AKCABAY, Deniz Tolga; CHAE, Eun Jung; YOUNG, Yin Lu; DUCOIN, Antoine; ASTOLFI, Jacques Andre
The objective of this work is to investigate the influence of cavity-induced vibrations on the dynamic response and stability of a NACA66 hydrofoil at 8° angle of attack at Re=750 000 via combined experimental measurements and numerical simulations. The rectangular, cantilevered hydrofoil is assumed to be rigid in the chordwise direction, while the spanwise bending and twisting deformations are represented using a two-degrees-of-freedom structural model. The multiphase flow is modeled with an incompressible, unsteady Reynolds Averaged Navier–Stokes solver with the k–ω Shear Stress Transport (SST) turbulence closure model, while the phase evolutions are modeled with a mass-transport equation based cavitation model. The numerical predictions are compared with experimental measurements across a range of cavitation numbers for a rigid and a flexible hydrofoil with the same undeformed geometries. The results showed that foil flexibility can lead to: (1) focusing – locking – of the frequency content of the vibrations to the nearest sub-harmonics of the foil׳s wetted natural frequencies, and (2) broadening of the frequency content of the vibrations in the unstable cavitation regime, where amplifications are observed in the sub-harmonics of the foil natural frequencies. Cavitation was also observed to cause frequency modulation, as the fluid density, and hence fluid induced (inertial, damping, and disturbing) forces fluctuated with unsteady cavitation.
2014-01-01T00:00:00ZAKCABAY, Deniz TolgaCHAE, Eun JungYOUNG, Yin LuDUCOIN, AntoineASTOLFI, Jacques AndreThe objective of this work is to investigate the influence of cavity-induced vibrations on the dynamic response and stability of a NACA66 hydrofoil at 8° angle of attack at Re=750 000 via combined experimental measurements and numerical simulations. The rectangular, cantilevered hydrofoil is assumed to be rigid in the chordwise direction, while the spanwise bending and twisting deformations are represented using a two-degrees-of-freedom structural model. The multiphase flow is modeled with an incompressible, unsteady Reynolds Averaged Navier–Stokes solver with the k–ω Shear Stress Transport (SST) turbulence closure model, while the phase evolutions are modeled with a mass-transport equation based cavitation model. The numerical predictions are compared with experimental measurements across a range of cavitation numbers for a rigid and a flexible hydrofoil with the same undeformed geometries. The results showed that foil flexibility can lead to: (1) focusing – locking – of the frequency content of the vibrations to the nearest sub-harmonics of the foil׳s wetted natural frequencies, and (2) broadening of the frequency content of the vibrations in the unstable cavitation regime, where amplifications are observed in the sub-harmonics of the foil natural frequencies. Cavitation was also observed to cause frequency modulation, as the fluid density, and hence fluid induced (inertial, damping, and disturbing) forces fluctuated with unsteady cavitation.CHARACTERIZATION OF A FLOW SEPARATION SENSOR ON A HYDROFOIL: THE HYDRO E-TELLTALEALAS, RémiVOISIN, DimitriSOULIER, AntoineBRAUD, CarolineMARCILLAT, PaulPEZERIL, BaudoinD'ARCO, FrançoisBOT, Patrickhttp://hdl.handle.net/10985/201712024-03-13T10:41:29Z2021-01-01T00:00:00ZCHARACTERIZATION OF A FLOW SEPARATION SENSOR ON A HYDROFOIL: THE HYDRO E-TELLTALE
ALAS, Rémi; VOISIN, Dimitri; SOULIER, Antoine; BRAUD, Caroline; MARCILLAT, Paul; PEZERIL, Baudoin; D'ARCO, François; BOT, Patrick
The performance of lifting bodies such as hydrofoils is determined by the flow state and particular attention should be paid to flow separation, as this greatly affects the generated lift and drag. Sailors are used to look at telltales (woolies) to trim their sails or steer their yacht. A French company developed an electronic telltale for sails based on a strain gauge activated by a silicon strand, with the appropriate signal processing to deliver the same information as a classical wool-made telltale, basically attached or separated flow. This new sensor proved useful when woolies are not visible or to deliver a signal to feed a control system, such as the autopilot for example. It was also applied to wind turbines to control the blade pitch. Mer Agitée is now developing an equivalent hydrodynamic e-Telltale to be used on hydrofoils and rudders to help trimming and controlling. The present work presents the investigation of a foil section fitted with this new sensor in a water tunnel, combining force and PIV measurements with the sensor signal, on a wide range of angle of attack. Results show that the hydro e-Telltale enables detecting the flow separation and anticipate stall, and possibly allows for detecting the boundary layer transition to turbulence. The feedback from this new sensor could be used for example in a control loop to make an “Anti-Stall System” on a rudder or a foil.
2021-01-01T00:00:00ZALAS, RémiVOISIN, DimitriSOULIER, AntoineBRAUD, CarolineMARCILLAT, PaulPEZERIL, BaudoinD'ARCO, FrançoisBOT, PatrickThe performance of lifting bodies such as hydrofoils is determined by the flow state and particular attention should be paid to flow separation, as this greatly affects the generated lift and drag. Sailors are used to look at telltales (woolies) to trim their sails or steer their yacht. A French company developed an electronic telltale for sails based on a strain gauge activated by a silicon strand, with the appropriate signal processing to deliver the same information as a classical wool-made telltale, basically attached or separated flow. This new sensor proved useful when woolies are not visible or to deliver a signal to feed a control system, such as the autopilot for example. It was also applied to wind turbines to control the blade pitch. Mer Agitée is now developing an equivalent hydrodynamic e-Telltale to be used on hydrofoils and rudders to help trimming and controlling. The present work presents the investigation of a foil section fitted with this new sensor in a water tunnel, combining force and PIV measurements with the sensor signal, on a wide range of angle of attack. Results show that the hydro e-Telltale enables detecting the flow separation and anticipate stall, and possibly allows for detecting the boundary layer transition to turbulence. The feedback from this new sensor could be used for example in a control loop to make an “Anti-Stall System” on a rudder or a foil.Bearing Fault Detection in DFIG-Based Wind Turbines Using the First Intrinsic Mode FunctionAMIRAT, YacineCHOQUEUSE, VincentBENBOUZID, MohamedCHARPENTIER, Jean-Frederichttp://hdl.handle.net/10985/88602023-01-13T01:22:25Z2010-01-01T00:00:00ZBearing Fault Detection in DFIG-Based Wind Turbines Using the First Intrinsic Mode Function
AMIRAT, Yacine; CHOQUEUSE, Vincent; BENBOUZID, Mohamed; CHARPENTIER, Jean-Frederic
Wind energy conversion systems have become a focal point in the research of renewable energy sources. In order to make the DFIG-based wind turbines so competitive as the classical electric power stations it is important to reduce the operational and maintenance costs by continuously monitoring the condition of these systems. This paper provides a method for bearing fault detection in DFIG-based wind turbines. The proposed method uses the first Intrinsic Mode Function (IMF) of the stator current signal. After extracting the first IMF, amplitude-demodulation is performed to reveal a generator bearing fault. Experimental results show that the proposed method significantly improves the result of classical amplitude-demodulation techniques for failure detection.
2010-01-01T00:00:00ZAMIRAT, YacineCHOQUEUSE, VincentBENBOUZID, MohamedCHARPENTIER, Jean-FredericWind energy conversion systems have become a focal point in the research of renewable energy sources. In order to make the DFIG-based wind turbines so competitive as the classical electric power stations it is important to reduce the operational and maintenance costs by continuously monitoring the condition of these systems. This paper provides a method for bearing fault detection in DFIG-based wind turbines. The proposed method uses the first Intrinsic Mode Function (IMF) of the stator current signal. After extracting the first IMF, amplitude-demodulation is performed to reveal a generator bearing fault. Experimental results show that the proposed method significantly improves the result of classical amplitude-demodulation techniques for failure detection.To curl or not to curl : wind tunnel investigation of spinnaker performanceAUBIN, NicolasAUGIER, BenoitDEPARDAY, JulienSACHER, Matthieuhttp://hdl.handle.net/10985/149192023-01-13T01:25:06Z2017-01-01T00:00:00ZTo curl or not to curl : wind tunnel investigation of spinnaker performance
AUBIN, Nicolas; AUGIER, Benoit; DEPARDAY, Julien; SACHER, Matthieu
This work presents a wind tunnel experimental study of the effect of curling on the spinnaker aerodynamic performance. Four spinnakers combining two different panellings and sail materials are tested at different wind speeds and wind angles in the Twisted Flow Wind Tunnel of the University of Auckland. Results show that the curling has a significant benefit on the propulsive force at an AWA 100° when this conclusion cannot be made at lower AWA where the best propulsive force is reached on the verge of curling or before. Sail material and panelling have an effect on the sheet length where curling appears, stiffer material and cross cut panelling being the latest to curl. Finally, it is shown that the curling frequency increased linearly with the flow speed at AWA = 120°.
2017-01-01T00:00:00ZAUBIN, NicolasAUGIER, BenoitDEPARDAY, JulienSACHER, MatthieuThis work presents a wind tunnel experimental study of the effect of curling on the spinnaker aerodynamic performance. Four spinnakers combining two different panellings and sail materials are tested at different wind speeds and wind angles in the Twisted Flow Wind Tunnel of the University of Auckland. Results show that the curling has a significant benefit on the propulsive force at an AWA 100° when this conclusion cannot be made at lower AWA where the best propulsive force is reached on the verge of curling or before. Sail material and panelling have an effect on the sheet length where curling appears, stiffer material and cross cut panelling being the latest to curl. Finally, it is shown that the curling frequency increased linearly with the flow speed at AWA = 120°.Inviscid approach for upwind sails aerodynamics. How far can we go?AUBIN, NicolasAUGIER, BenoitHAUVILLE, FrédéricFLOCH, RonanBOT, Patrickhttp://hdl.handle.net/10985/110172024-03-13T10:41:28Z2016-01-01T00:00:00ZInviscid approach for upwind sails aerodynamics. How far can we go?
AUBIN, Nicolas; AUGIER, Benoit; HAUVILLE, Frédéric; FLOCH, Ronan; BOT, Patrick
This work presents a full-scale experimental study of a yacht rig and sails in real upwind sailing conditions and a comparison with Fluid Structure Interaction (FSI) simulations with the ARAVANTI model (Finite Element Method for the structure and Vortex Lattice Method for the fluid). An specific on-board instrumentation system simultaneously measures loads in the rig and sails, sailing data (wind, boat attitude and speed) and the shape of sails in real navigation conditions (flying shape). Flying shape parameters are extracted using the camera-based VSPARS system to characterize the effects of sail trims and to be compared with the results of the simulation. The potential flow solver gives fast and accurate predictions of both the flying shape and the loads in the rig in most conditions. The inviscid approach, commonly used in the early stage of design, must be checked, as in particular cases where the sails are heavily loaded, flow separation is significant and results from a potential flow solver are inaccurate. A new version of the model including the heel angle as an additional degree of freedom in the structural solver enables to detect when the inviscid flow approach overestimates the aerodynamic load. This upgrade improves the utility and reliability of the inviscid flow approach which remains relevant at the early stages of design as it is much more cost-effective than RANS models.
2016-01-01T00:00:00ZAUBIN, NicolasAUGIER, BenoitHAUVILLE, FrédéricFLOCH, RonanBOT, PatrickThis work presents a full-scale experimental study of a yacht rig and sails in real upwind sailing conditions and a comparison with Fluid Structure Interaction (FSI) simulations with the ARAVANTI model (Finite Element Method for the structure and Vortex Lattice Method for the fluid). An specific on-board instrumentation system simultaneously measures loads in the rig and sails, sailing data (wind, boat attitude and speed) and the shape of sails in real navigation conditions (flying shape). Flying shape parameters are extracted using the camera-based VSPARS system to characterize the effects of sail trims and to be compared with the results of the simulation. The potential flow solver gives fast and accurate predictions of both the flying shape and the loads in the rig in most conditions. The inviscid approach, commonly used in the early stage of design, must be checked, as in particular cases where the sails are heavily loaded, flow separation is significant and results from a potential flow solver are inaccurate. A new version of the model including the heel angle as an additional degree of freedom in the structural solver enables to detect when the inviscid flow approach overestimates the aerodynamic load. This upgrade improves the utility and reliability of the inviscid flow approach which remains relevant at the early stages of design as it is much more cost-effective than RANS models.Wind tunnel investigation of dynamic trimming on upwind sail aerodynamicsAUBIN, NicolasAUGIER, BenoitSACHER, MatthieuHAUVILLE, FrédéricFLAY, Richard G.J.BOT, Patrickhttp://hdl.handle.net/10985/125602024-03-13T10:41:26Z2017-01-01T00:00:00ZWind tunnel investigation of dynamic trimming on upwind sail aerodynamics
AUBIN, Nicolas; AUGIER, Benoit; SACHER, Matthieu; HAUVILLE, Frédéric; FLAY, Richard G.J.; BOT, Patrick
An experiment was performed in the Yacht Research Unit’s Twisted Flow Wind Tunnel (University of Auckland) to test the effect of dynamic trimming on three IMOCA 60 inspired mainsail models in an upwind ( AW = 60°) unheeled configuration. This study presents dynamic fluid structure interaction results in well controlled conditions (wind, sheet length) with a dynamic trimming system. Trimming oscillations are done around an optimum value of CFobj previously found with a static trim. Different oscillation amplitudes and frequencies of trimming are investigated. Measurements are done with a 6 component force balance and a load sensor giving access to the unsteady mainsail sheet load. The driving CFx and optimization target CFobj coefficient first decrease at low reduced frequency fr for quasi-steady state then increase, becoming higher than the static state situation. The driving force CFx and the optimization target coefficient CFobj show an optimum for the three different design sail shapes located at fr = 0.255. This optimum is linked to the power transmitted to the rig and sail system by the trimming device. The effect of the camber of the design shape is also investigated. The flat mainsail design benefits more than the other mainsail designs from the dynamic trimming compared to their respective static situtation. This study presents dynamic results that cannot be accurately predicted with a quasi-static approach. These results are therefore valuable for future FSI numerical tools validations in unsteady conditions.
2017-01-01T00:00:00ZAUBIN, NicolasAUGIER, BenoitSACHER, MatthieuHAUVILLE, FrédéricFLAY, Richard G.J.BOT, PatrickAn experiment was performed in the Yacht Research Unit’s Twisted Flow Wind Tunnel (University of Auckland) to test the effect of dynamic trimming on three IMOCA 60 inspired mainsail models in an upwind ( AW = 60°) unheeled configuration. This study presents dynamic fluid structure interaction results in well controlled conditions (wind, sheet length) with a dynamic trimming system. Trimming oscillations are done around an optimum value of CFobj previously found with a static trim. Different oscillation amplitudes and frequencies of trimming are investigated. Measurements are done with a 6 component force balance and a load sensor giving access to the unsteady mainsail sheet load. The driving CFx and optimization target CFobj coefficient first decrease at low reduced frequency fr for quasi-steady state then increase, becoming higher than the static state situation. The driving force CFx and the optimization target coefficient CFobj show an optimum for the three different design sail shapes located at fr = 0.255. This optimum is linked to the power transmitted to the rig and sail system by the trimming device. The effect of the camber of the design shape is also investigated. The flat mainsail design benefits more than the other mainsail designs from the dynamic trimming compared to their respective static situtation. This study presents dynamic results that cannot be accurately predicted with a quasi-static approach. These results are therefore valuable for future FSI numerical tools validations in unsteady conditions.