SAM
https://sam.ensam.eu:443
The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.2024-03-24T15:38:13Z3D Human Pose Estimation with a Catadioptric Sensor in Unconstrained Environments Using an Annealed Particle Filter
http://hdl.handle.net/10985/19775
3D Human Pose Estimation with a Catadioptric Sensor in Unconstrained Environments Using an Annealed Particle Filter
ABABSA, Fakhreddine; HADJ-ABDELKADER, Hicham; BOUI, Marouane
The purpose of this paper is to investigate the problem of 3D human tracking in complex environments using a particle filter with images captured by a catadioptric vision system. This issue has been widely studied in the literature on RGB images acquired from conventional perspective cameras, while omnidirectional images have seldom been used and published research works in this field remains limited. In this study, the Riemannian varieties was considered in order to compute the gradient on spherical images and generate a robust descriptor used along with an SVM classifier for human detection. Original likelihood functions associated with the particle filter are proposed, using both geodesic distances and overlapping regions between the silhouette detected in the images and the projected 3D human model. Our approach was experimentally evaluated on real data and showed favorable results compared to machine learning based techniques about the 3D pose accuracy. Thus, the Root Mean Square Error (RMSE) was measured by comparing estimated 3D poses and truth data, resulting in a mean error of 0.065 m when walking action was applied.
2020-01-01T00:00:00ZABABSA, FakhreddineHADJ-ABDELKADER, HichamBOUI, MarouaneThe purpose of this paper is to investigate the problem of 3D human tracking in complex environments using a particle filter with images captured by a catadioptric vision system. This issue has been widely studied in the literature on RGB images acquired from conventional perspective cameras, while omnidirectional images have seldom been used and published research works in this field remains limited. In this study, the Riemannian varieties was considered in order to compute the gradient on spherical images and generate a robust descriptor used along with an SVM classifier for human detection. Original likelihood functions associated with the particle filter are proposed, using both geodesic distances and overlapping regions between the silhouette detected in the images and the projected 3D human model. Our approach was experimentally evaluated on real data and showed favorable results compared to machine learning based techniques about the 3D pose accuracy. Thus, the Root Mean Square Error (RMSE) was measured by comparing estimated 3D poses and truth data, resulting in a mean error of 0.065 m when walking action was applied.Augmented Reality Application in Manufacturing Industry: Maintenance and Non-destructive Testing (NDT) Use Cases
http://hdl.handle.net/10985/19418
Augmented Reality Application in Manufacturing Industry: Maintenance and Non-destructive Testing (NDT) Use Cases
ABABSA, Fakhreddine
In recent years, a structural transformation of the manufacturing industry has been occurring as a result of the digital revolution. Thus, digital tools are now systematically used throughout the entire value chain, from design to production to marketing, especially virtual and augmented reality. Therefore, the purpose of this paper is to review, through concrete use cases, the progress of these novel technologies and their use in the manufacturing industry.
2020-01-01T00:00:00ZABABSA, FakhreddineIn recent years, a structural transformation of the manufacturing industry has been occurring as a result of the digital revolution. Thus, digital tools are now systematically used throughout the entire value chain, from design to production to marketing, especially virtual and augmented reality. Therefore, the purpose of this paper is to review, through concrete use cases, the progress of these novel technologies and their use in the manufacturing industry.3D Human Tracking with Catadioptric Omnidirectional Camera
http://hdl.handle.net/10985/16195
3D Human Tracking with Catadioptric Omnidirectional Camera
ABABSA, Fakhreddine; HADJ-ABDELKADER, Hicham; BOUI, Marouane
This paper deals with the problem of 3D human tracking in catadioptric images using particle-filtering framework. While traditional perspective images are well exploited, only a few methods have been developed for catadioptric vision, for the human detection or tracking problems. We propose to extend the 3D pose estimation in the case of perspective cameras to catadioptric sensors. In this paper, we develop an original likelihood functions based, on the one hand, on the geodetic distance in the spherical space SO3 and, on the other hand, on the mapping between the human silhouette in the images and the projected 3D model. These likelihood functions combined with a particle filter, whose propagation model is adapted to the spherical space, allow accurate 3D human tracking in omnidirectional images. Both visual and quantitative analysis of the experimental results demonstrate the effectiveness of our approach.
2019-01-01T00:00:00ZABABSA, FakhreddineHADJ-ABDELKADER, HichamBOUI, MarouaneThis paper deals with the problem of 3D human tracking in catadioptric images using particle-filtering framework. While traditional perspective images are well exploited, only a few methods have been developed for catadioptric vision, for the human detection or tracking problems. We propose to extend the 3D pose estimation in the case of perspective cameras to catadioptric sensors. In this paper, we develop an original likelihood functions based, on the one hand, on the geodetic distance in the spherical space SO3 and, on the other hand, on the mapping between the human silhouette in the images and the projected 3D model. These likelihood functions combined with a particle filter, whose propagation model is adapted to the spherical space, allow accurate 3D human tracking in omnidirectional images. Both visual and quantitative analysis of the experimental results demonstrate the effectiveness of our approach.Combining HoloLens and Leap-Motion for Free Hand-Based 3D Interaction in MR Environments
http://hdl.handle.net/10985/19485
Combining HoloLens and Leap-Motion for Free Hand-Based 3D Interaction in MR Environments
ABABSA, Fakhreddine; HE, Junhui; CHARDONNET, Jean-Rémy
The ability to interact with virtual objects using gestures would allow users to improve their experience in Mixed Reality (MR) environments, especially when they use AR headsets. Today, MR head-mounted displays like the HoloLens integrate hand gesture based interaction allowing users to take actions in MR environments. However, the proposed interactions remain limited. In this paper, we propose to combine a Leap Motion Controller (LMC) with a HoloLens in order to improve gesture interaction with virtual objects. Two main issues are presented: an interactive calibration procedure for the coupled HoloLens-LMC device and an intuitive hand-based interaction approach using LMC data in the HoloLens environment. A set of first experiments was carried out to evaluate the accuracy and the usability of the proposed approach.
2020-01-01T00:00:00ZABABSA, FakhreddineHE, JunhuiCHARDONNET, Jean-RémyThe ability to interact with virtual objects using gestures would allow users to improve their experience in Mixed Reality (MR) environments, especially when they use AR headsets. Today, MR head-mounted displays like the HoloLens integrate hand gesture based interaction allowing users to take actions in MR environments. However, the proposed interactions remain limited. In this paper, we propose to combine a Leap Motion Controller (LMC) with a HoloLens in order to improve gesture interaction with virtual objects. Two main issues are presented: an interactive calibration procedure for the coupled HoloLens-LMC device and an intuitive hand-based interaction approach using LMC data in the HoloLens environment. A set of first experiments was carried out to evaluate the accuracy and the usability of the proposed approach.Free Hand-Based 3D Interaction in Optical See-Through Augmented Reality Using Leap Motion
http://hdl.handle.net/10985/14475
Free Hand-Based 3D Interaction in Optical See-Through Augmented Reality Using Leap Motion
ABABSA, Fakhreddine; HE, Junhui; CHARDONNET, Jean-Rémy
In augmented reality environments, the natural hand interaction between a virtual object and the user is a major issue to manipulate a rendered object in a convenient way. Microsoft’s HoloLens (Microsoft 2018) is an innovative augmented reality (AR) device that has provided an impressive experience for the user. However, the gesture interactions offered to the user are very limited. HoloLens currently recognizes two core component gestures: Air tap and Bloom. To solve this issue, we propose to integrate a Leap Motion Controller (LMC) within the HoloLens device (Figure 1). We thus used 3D hand and finger tracking provided by the LMC to propose new free hand-based interaction more natural and intuitive. We implemented three fully 3D techniques for selection, translation and rotation manipulation. In this work, we first investigated how to combine the two devices to get them working together in real time, and then we evaluated the proposed 3D hand interactions.
2018-01-01T00:00:00ZABABSA, FakhreddineHE, JunhuiCHARDONNET, Jean-RémyIn augmented reality environments, the natural hand interaction between a virtual object and the user is a major issue to manipulate a rendered object in a convenient way. Microsoft’s HoloLens (Microsoft 2018) is an innovative augmented reality (AR) device that has provided an impressive experience for the user. However, the gesture interactions offered to the user are very limited. HoloLens currently recognizes two core component gestures: Air tap and Bloom. To solve this issue, we propose to integrate a Leap Motion Controller (LMC) within the HoloLens device (Figure 1). We thus used 3D hand and finger tracking provided by the LMC to propose new free hand-based interaction more natural and intuitive. We implemented three fully 3D techniques for selection, translation and rotation manipulation. In this work, we first investigated how to combine the two devices to get them working together in real time, and then we evaluated the proposed 3D hand interactions.Vibration Analysis of Euler-Bernoulli Beams Partially Immersed in a Viscous Fluid
http://hdl.handle.net/10985/11185
Vibration Analysis of Euler-Bernoulli Beams Partially Immersed in a Viscous Fluid
ABASSI, Wafik; RAZAFIMAHERY, Fulgence; EL BAROUDI, Adil
The vibrational characteristics of a microbeam are well known to strongly depend on the fluid in which the beam is immersed. In this paper, we present a detailed theoretical study of the modal analysis of microbeams partially immersed in a viscous fluid. A fixed-free microbeamvibrating in a viscous fluid is modeled using the Euler-Bernoulli equation for the beams.The unsteady Stokes equations are solved using a Helmholtz decomposition technique in a two-dimensional plane containing the microbeams cross sections.The symbolic softwareMathematica is used in order to find the coupled vibration frequencies of beams with two portions. The frequency equation is deduced and analytically solved.The finite element method using ComsolMultiphysics software results is compared with present method for validation and an acceptable match between them was obtained. In the eigenanalysis, the frequency equation is generated by satisfying all boundary conditions. It is shown that the present formulation is an appropriate and new approach to tackle the problem with good accuracy.
2016-01-01T00:00:00ZABASSI, WafikRAZAFIMAHERY, FulgenceEL BAROUDI, AdilThe vibrational characteristics of a microbeam are well known to strongly depend on the fluid in which the beam is immersed. In this paper, we present a detailed theoretical study of the modal analysis of microbeams partially immersed in a viscous fluid. A fixed-free microbeamvibrating in a viscous fluid is modeled using the Euler-Bernoulli equation for the beams.The unsteady Stokes equations are solved using a Helmholtz decomposition technique in a two-dimensional plane containing the microbeams cross sections.The symbolic softwareMathematica is used in order to find the coupled vibration frequencies of beams with two portions. The frequency equation is deduced and analytically solved.The finite element method using ComsolMultiphysics software results is compared with present method for validation and an acceptable match between them was obtained. In the eigenanalysis, the frequency equation is generated by satisfying all boundary conditions. It is shown that the present formulation is an appropriate and new approach to tackle the problem with good accuracy.Torsional Vibrations of Fluid-Filled Multilayered Transversely Isotropic Finite Circular Cylinder
http://hdl.handle.net/10985/11186
Torsional Vibrations of Fluid-Filled Multilayered Transversely Isotropic Finite Circular Cylinder
ABASSI, Wafik; RAZAFIMAHERY, Fulgence; EL BAROUDI, Adil
An analytical and numerical study for the torsional vibrations of viscous fluid-filled three-layer transversely isotropic cylinder is presented in this paper. The equations of motion of solid and fluid are respectively formulated using the constitutive equations of a transversely isotropic cylinder and the constitutive equations of a viscous fluid. The analytical solution of the frequency equation is obtained using the boundary conditions at the free surface of the solid layer and the boundary conditions at the fluid–solid interface. The frequency equation is deduced and analytically solved using the symbolic Software Mathematica. The finite element method using Comsol Multiphysics Software results are compared with present method for validation and an acceptable match between them were obtained. It is shown that the results from the proposed method are in good agreement with numerical solutions. The influence of fluid dynamic viscosity is thoroughly analyzed and the effect of the isotropic properties on the natural frequencies is also investigated.
2016-01-01T00:00:00ZABASSI, WafikRAZAFIMAHERY, FulgenceEL BAROUDI, AdilAn analytical and numerical study for the torsional vibrations of viscous fluid-filled three-layer transversely isotropic cylinder is presented in this paper. The equations of motion of solid and fluid are respectively formulated using the constitutive equations of a transversely isotropic cylinder and the constitutive equations of a viscous fluid. The analytical solution of the frequency equation is obtained using the boundary conditions at the free surface of the solid layer and the boundary conditions at the fluid–solid interface. The frequency equation is deduced and analytically solved using the symbolic Software Mathematica. The finite element method using Comsol Multiphysics Software results are compared with present method for validation and an acceptable match between them were obtained. It is shown that the results from the proposed method are in good agreement with numerical solutions. The influence of fluid dynamic viscosity is thoroughly analyzed and the effect of the isotropic properties on the natural frequencies is also investigated.Comparaison des actionneurs
http://hdl.handle.net/10985/9238
Comparaison des actionneurs
ABBA, Gabriel
Les objectifs de ce rapport sont donc multiples. En premier, le rapport établie la méthodologie de sélection des actionneurs d’un robot en fonction d’un ou plusieurs critères à satisfaire tout en respectant les contraintes nécessaires au bon fonctionnement du robot, contraintes elles mêmes liées très fortement aux performances dynamiques exigées du robot et aux différentes tâches auxquelles le robot est destiné. Il est facile de montrer que la sélection des actionneurs est fortement liée aux choix technologiques des dispositifs de transmission des mouvements et de la technologie même desdits actionneurs. Le second objectif du rapport est par conséquent d’élaborer une méthode de sélection couplée des actionneurs et des transmissions. Pour se faire, nous limitons délibérément les choix à certaines technologies. Enfin, le dernier objectif du rapport est de proposer un modèle physique approché mais néanmoins le plus précis possible du comportement énergétique de l’ensemble de la chaîne de transmission des mouvements et donc un modèle énergétique des actionneurs, des transmissions cinématiques jusqu’aux variables articulaires du robot.
2012-01-01T00:00:00ZABBA, GabrielLes objectifs de ce rapport sont donc multiples. En premier, le rapport établie la méthodologie de sélection des actionneurs d’un robot en fonction d’un ou plusieurs critères à satisfaire tout en respectant les contraintes nécessaires au bon fonctionnement du robot, contraintes elles mêmes liées très fortement aux performances dynamiques exigées du robot et aux différentes tâches auxquelles le robot est destiné. Il est facile de montrer que la sélection des actionneurs est fortement liée aux choix technologiques des dispositifs de transmission des mouvements et de la technologie même desdits actionneurs. Le second objectif du rapport est par conséquent d’élaborer une méthode de sélection couplée des actionneurs et des transmissions. Pour se faire, nous limitons délibérément les choix à certaines technologies. Enfin, le dernier objectif du rapport est de proposer un modèle physique approché mais néanmoins le plus précis possible du comportement énergétique de l’ensemble de la chaîne de transmission des mouvements et donc un modèle énergétique des actionneurs, des transmissions cinématiques jusqu’aux variables articulaires du robot.Design Elements for high speed SRM
http://hdl.handle.net/10985/11995
Design Elements for high speed SRM
ABBA, Gabriel; ANTOINE, Jean-François; SAUVEY, Christophe; VISA, Codrut
This paper deals with the study of high speed switched reluctance motors and their pre-dimensioning. The predimensioning is tackled towards the inductance profile and the torque generation. Then, the power density is assessed in terms of three defined fundamental parameters, each depending on electrical, mechanical and geometrical design of the motor. The mechanical limitations studied are the centrifugal stresses and the vibratory behavior of the motor. A shape optimization of the rotor teeth leans then on a coupled magnetic-mechanic coupled problem, solved with finite elements simulations. After that,mechanic, magnetic and copper losses are given in terms of the rotor external volume so as to assess the weight of each heat source in the global motor heating. Once all the losses are linked to temperature, a criterion to improve the ability to develop a high speed motor is finally proposed.
2004-01-01T00:00:00ZABBA, GabrielANTOINE, Jean-FrançoisSAUVEY, ChristopheVISA, CodrutThis paper deals with the study of high speed switched reluctance motors and their pre-dimensioning. The predimensioning is tackled towards the inductance profile and the torque generation. Then, the power density is assessed in terms of three defined fundamental parameters, each depending on electrical, mechanical and geometrical design of the motor. The mechanical limitations studied are the centrifugal stresses and the vibratory behavior of the motor. A shape optimization of the rotor teeth leans then on a coupled magnetic-mechanic coupled problem, solved with finite elements simulations. After that,mechanic, magnetic and copper losses are given in terms of the rotor external volume so as to assess the weight of each heat source in the global motor heating. Once all the losses are linked to temperature, a criterion to improve the ability to develop a high speed motor is finally proposed.Résolution numérique de l’écoulement diphasique en milieu poreux hétérogène incluant les effets inertiels
http://hdl.handle.net/10985/10029
Résolution numérique de l’écoulement diphasique en milieu poreux hétérogène incluant les effets inertiels
ABBASIAN ARANI, Ali Akbar; LASSEUX, Didier; AHMADI-SENICHAULT, Azita
La mise en place d'un outil numérique 3D de simulation d'écoulement diphasique hors régime de Darcy basé sur le modèle de Darcy-Forchheimer généralisé est présentée. L'outil est tout d’abord validé à l’aide d'une solution semi analytique 1D de type Buckley-Leverett. Des résultats obtenus dans différentes configurations homogène et hétérogènes 1D et 2D mettent en évidence l'importance des termes inertiels en fonction d'un nombre de Reynolds de l'écoulement.
2007-01-01T00:00:00ZABBASIAN ARANI, Ali AkbarLASSEUX, DidierAHMADI-SENICHAULT, AzitaLa mise en place d'un outil numérique 3D de simulation d'écoulement diphasique hors régime de Darcy basé sur le modèle de Darcy-Forchheimer généralisé est présentée. L'outil est tout d’abord validé à l’aide d'une solution semi analytique 1D de type Buckley-Leverett. Des résultats obtenus dans différentes configurations homogène et hétérogènes 1D et 2D mettent en évidence l'importance des termes inertiels en fonction d'un nombre de Reynolds de l'écoulement.