The Experts below are selected from a list of 2385 Experts worldwide ranked by ideXlab platform

Vu Dinh-son - One of the best experts on this subject based on the ideXlab platform.

  • Synthèse sur la conception, commande et planification de trajectoire d’une interface de locomotion pour la réadaptation de la marche
    Université Laval, 2017
    Co-Authors: Vu Dinh-son
    Abstract:

    Cette thèse synthétise la conception d’une plateforme de marche destinée à la réadaptation des membres inférieurs pour le mouvement de la marche. L’automatisation du travail des thérapeutes, la réduction de leur charge de travail et la diversification des exercices pour les patients est un atout par rapport aux outils existants sur le marché tels que les tapis roulants ou les allées instrumentées pour la réadaptation. La conception d’une interface de locomotion pour la simulation de la marche présente des défis en terme de performance et de stabilité du mécanisme, de même que pour assurer la sécurité de l’utilisateur. L’équilibre de l’utilisateur doit être préservé grâce à une interaction humain-robot souple durant la phase d’élancement du pied et une sensation de rigidité lors de la phase d’appui. Dans un premier temps, la thèse présente le mouvement de la marche humaine pour trois types de milieux, c’est-à-dire la marche au sol, la marche d’escalier ascendante et la marche d’escalier descendante. Entre autres, le chapitre 1 cible les points essentiels de la cinématique et de la dynamique des membres inférieurs afin d’établir les exigences physiques pour la conception de la plateforme de marche. Le chapitre 2 introduit l’architecture mécanique de l’interface de locomotion basé sur deux systèmes indépendants de courroies déplaçant les deux effecteurs dans les translations horizontale et verticale, correspondant au plan sagittal dans lequel la majeure partie du mouvement de marche s’effectue. L’architecture du routage de courroies découple les degrés de liberté et simplifie ainsi la commande de la plateforme en séparant chaque degré de liberté en système indépendant. Cette architecture augmente également le rendement des efforts articulaires transmis aux effecteurs comparativement à un système dont les degrés de liberté sont co-dépendants. La thèse introduit ensuite la commande mise en place pour l’interaction entre le mécanisme et l’opérateur. Les exigences cinématiques et dynamiques diffèrent selon la phase d’élancement et la phase d’appui de la marche. Ainsi, le chapitre 3 présente la stratégie mise en place dans la direction horizontale pour minimiser les forces d’interaction entre l’utilisateur et l’effecteur. La commande en force permet, dans un premier temps, de diminuer l’inertie Apparente de l’effecteur ressentie par l’utilisateur. Par la suite, un mécanisme passif à câbles est utilisé en tant qu’interface pour réduire davantage l’impédance ressentie du système. Le chapitre 4, quant à lui, décrit la stratégie mise en place pour gérer la phase d’appui de la marche afin de générer la contrainte rigide nécessaire à la simulation du sol virtuel. Le chapitre introduit la commande pour générer la limite virtuelle ainsi que la mise en place du système d’équilibrage statique à ressort à gaz pour diminuer le travail des moteurs et supporter le poids de la personne. Finalement, le chapitre 5 introduit la commande haut niveau pour générer le mouvement infini sur l’interface de locomotion avec un algorithme de recul, ramenant l’utilisateur dans la direction opposée à son mouvement pour générer l’espace nécessaire aux prochaines phases de marche, dans la direction horizontale comme pour le fonctionnement d’un tapis de course et dans la direction verticale, comme pour le fonctionnement d’un escalier mécanique inversé.This thesis summarizes the design of a locomotion interface for gait rehabilitation. The aim of the mechanism is to alleviate the workload of therapists by automating the repetitive movements involved in the rehabilitation exercises. Moreover, by offering a larger panel of exercises, the locomotion interface should be an asset compared to standard treadmills or rehabilitation walkways. Walking simulation is a challenge in terms of performance, power and safety since the mechanism includes the user in the workspace of the effectors. The balance of the user should be ensured during the swing phase with a reduced human-robot interaction and reliable during the stance phase. First, Chapter 1 describes the walking motion, the stair climbing up and down movement and highlights their main kinematic and dynamic features. Chapter 2 then introduces the architecture of the locomotion interface based on independent belt routings which transmit the movement to two end-effectors that carry the user. Each foot platform has two degrees of freedom (dofs) corresponding to the horizontal and vertical translations in the sagittal plane. Decoupling the dofs simplifies the control of the locomotion interface and increases the efficiency of the torque of the motor sent to the end-effectors compared to systems with co-dependent degrees-of-freedom. Then, the thesis presents the strategies used to supervise the human-robot interaction. The kinematic and dynamic requirements are different during the swing phase and the stance phase of the human gait. Therefore, Chapter 3 introduces the force controllers that lighten the Apparent Inertia of the mechanism as well as the additional mechanism based on passive cables in order to further alleviate the impedance of the effector. Chapter 4 presents the controller that generates the vertical virtual constraint in order to produce the required reliable floor during the stance phase. The rendering of the virtual environment is improved with the implementation of a static balancing system based on gas springs that alleviates the workload of the motors that handle the weight of the user. Finally, Chapter 5 introduces the cancellation algorithm that generates the infinite environment. Horizontally, the user is brought backward such as on a treadmill. Vertically, the user is moved in the opposite direction of his/her movement such as in a reversed escalator.Prix: Tableau d’honneur de la FÉS

  • Synthèse sur la conception, commande et planification de trajectoire d'une interface de locomotion pour la réadaptation de la marche
    Bibliotheque de l' Universite Laval, 2017
    Co-Authors: Vu Dinh-son
    Abstract:

    Tableau d'honneur de la Faculté des études supérieures et postdorales, 2016-2017Cette thèse synthétise la conception d'une plateforme de marche destinée à la réadaptation des membres inférieurs pour le mouvement de la marche. L'automatisation du travail des thérapeutes, la réduction de leur charge de travail et la diversification des exercices pour les patients est un atout par rapport aux outils existants sur le marché tels que les tapis roulants ou les allées instrumentées pour la réadaptation. La conception d'une interface de locomotion pour la simulation de la marche présente des défis en terme de performance et de stabilité du mécanisme, de même que pour assurer la sécurité de l'utilisateur. L'équilibre de l'utilisateur doit être préservé grâce à une interaction humain-robot souple durant la phase d'élancement du pied et une sensation de rigidité lors de la phase d'appui. Dans un premier temps, la thèse présente le mouvement de la marche humaine pour trois types de milieux, c'est-à-dire la marche au sol, la marche d'escalier ascendante et la marche d'escalier descendante. Entre autres, le chapitre 1 cible les points essentiels de la cinématique et de la dynamique des membres inférieurs afin d'établir les exigences physiques pour la conception de la plateforme de marche. Le chapitre 2 introduit l'architecture mécanique de l'interface de locomotion basé sur deux systèmes indépendants de courroies déplaçant les deux effecteurs dans les translations horizontale et verticale, correspondant au plan sagittal dans lequel la majeure partie du mouvement de marche s'effectue. L'architecture du routage de courroies découple les degrés de liberté et simplifie ainsi la commande de la plateforme en séparant chaque degré de liberté en système indépendant. Cette architecture augmente également le rendement des efforts articulaires transmis aux effecteurs comparativement à un système dont les degrés de liberté sont co-dépendants. La thèse introduit ensuite la commande mise en place pour l'interaction entre le mécanisme et l'opérateur. Les exigences cinématiques et dynamiques diffèrent selon la phase d'élancement et la phase d'appui de la marche. Ainsi, le chapitre 3 présente la stratégie mise en place dans la direction horizontale pour minimiser les forces d'interaction entre l'utilisateur et l'effecteur. La commande en force permet, dans un premier temps, de diminuer l'inertie Apparente de l'effecteur ressentie par l'utilisateur. Par la suite, un mécanisme passif à câbles est utilisé en tant qu'interface pour réduire davantage l'impédance ressentie du système. Le chapitre 4, quant à lui, décrit la stratégie mise en place pour gérer la phase d'appui de la marche afin de générer la contrainte rigide nécessaire à la simulation du sol virtuel. Le chapitre introduit la commande pour générer la limite virtuelle ainsi que la mise en place du système d'équilibrage statique à ressort à gaz pour diminuer le travail des moteurs et supporter le poids de la personne. Finalement, le chapitre 5 introduit la commande haut niveau pour générer le mouvement infini sur l'interface de locomotion avec un algorithme de recul, ramenant l'utilisateur dans la direction opposée à son mouvement pour générer l'espace nécessaire aux prochaines phases de marche, dans la direction horizontale comme pour le fonctionnement d'un tapis de course et dans la direction verticale, comme pour le fonctionnement d'un escalier mécanique inversé.This thesis summarizes the design of a locomotion interface for gait rehabilitation. The aim of the mechanism is to alleviate the workload of therapists by automating the repetitive movements involved in the rehabilitation exercises. Moreover, by offering a larger panel of exercises, the locomotion interface should be an asset compared to standard treadmills or rehabilitation walkways. Walking simulation is a challenge in terms of performance, power and safety since the mechanism includes the user in the workspace of the effectors. The balance of the user should be ensured during the swing phase with a reduced human-robot interaction and reliable during the stance phase. First, Chapter 1 describes the walking motion, the stair climbing up and down movement and highlights their main kinematic and dynamic features. Chapter 2 then introduces the architecture of the locomotion interface based on independent belt routings which transmit the movement to two end-effectors that carry the user. Each foot platform has two degrees of freedom (dofs) corresponding to the horizontal and vertical translations in the sagittal plane. Decoupling the dofs simplifies the control of the locomotion interface and increases the efficiency of the torque of the motor sent to the end-effectors compared to systems with co-dependent degrees-of-freedom. Then, the thesis presents the strategies used to supervise the human-robot interaction. The kinematic and dynamic requirements are different during the swing phase and the stance phase of the human gait. Therefore, Chapter 3 introduces the force controllers that lighten the Apparent Inertia of the mechanism as well as the additional mechanism based on passive cables in order to further alleviate the impedance of the effector. Chapter 4 presents the controller that generates the vertical virtual constraint in order to produce the required reliable floor during the stance phase. The rendering of the virtual environment is improved with the implementation of a static balancing system based on gas springs that alleviates the workload of the motors that handle the weight of the user. Finally, Chapter 5 introduces the cancellation algorithm that generates the infinite environment. Horizontally, the user is brought backward such as on a treadmill. Vertically, the user is moved in the opposite direction of his/her movement such as in a reversed escalator

Dongjun Lee - One of the best experts on this subject based on the ideXlab platform.

  • passive bilateral control and tool dynamics rendering for nonlinear mechanical teleoperators
    IEEE Transactions on Robotics, 2005
    Co-Authors: Dongjun Lee
    Abstract:

    We propose a passive bilateral teleoperation control law for a pair of n-degree-of-freedom (DOF) nonlinear robotic systems. The control law ensures energetic passivity of the closed-loop teleoperator with power scaling, coordinates motions of the master and slave robots, and installs useful task-specific dynamics for Inertia scaling, motion guidance, and obstacle avoidance. Consequently, the closed-loop teleoperator behaves like a common passive mechanical tool. A key innovation is the passive decomposition, which decomposes the 2n-DOF nonlinear teleoperator dynamics into two robot-like systems without violating passivity: an n-DOF shape system representing the master-slave position coordination aspect, and an n-DOF locked system representing the dynamics of the coordinated teleoperator. The master-slave position coordination is then achieved by regulating the shape system, while programmable Apparent Inertia of the coordinated teleoperator is achieved by scaling the Inertia of the locked system. To achieve this perfect coordination and Inertia scaling, the proposed control law measures and compensates for environment and human forcing. Passive velocity field control and artificial potential field control are used to implement guidance and obstacle avoidance for the coordinated teleoperator. The designed control is also implemented in an intrinsically passive negative semidefinite structure to ensure energetic passivity of the closed-loop teleoperator, even in the presence of parametric model uncertainties and inaccurate force sensing. Experiments are performed to validate the properties of the proposed control framework.

  • Passive bilateral feedforward control of linear dynamically similar teleoperated manipulators
    IEEE Transactions on Robotics and Automation, 2003
    Co-Authors: Dongjun Lee, Perry Y. Li
    Abstract:

    Presents a passive bilateral feedforward control scheme for linear dynamically similar (LDS) teleoperated manipulators with kinematic scaling and power scaling. The proposed control law renders the teleoperator as a passive rigid mechanical tool with programmable Apparent Inertia to the human operator and the work environment by utilizing bilateral force feedforward and kinematic feedback control. The passivity of the closed-loop system is robust to force measurement inaccuracies and model uncertainty. Thus, interaction stability of the teleoperator with any passive environment is guaranteed. Coordination error and the overall motion aspects of teleoperation are controlled individually. The proposed control law is also applicable to general nonlinear robotic teleoperators if sufficiently high kinematic feedback gains are used. The proposed control schemes have been validated experimentally for both LDS and non-LDS systems.

Marcia K. O'malley - One of the best experts on this subject based on the ideXlab platform.

  • Design of a haptic arm exoskeleton for training and rehabilitation
    IEEE ASME Transactions on Mechatronics, 2006
    Co-Authors: Abhishek Gupta, Marcia K. O'malley
    Abstract:

    A high-quality haptic interface is typically characterized by low Apparent Inertia and damping, high structural stiffness, minimal backlash, and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of space and weight limitations, workspace requirements, and the kinematic constraints placed on the device by the human arm. These constraints impose conflicting design requirements on the engineer attempting to design an arm exoskeleton. In this paper, the authors present a detailed review of the requirements and constraints that are involved in the design of a high-quality haptic arm exoskeleton. In this context, the design of a five-degree-of-freedom haptic arm exoskeleton for training and rehabilitation in virtual environments is presented. The device is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training. Motivation for such applications is based on findings that show robot-assisted physical therapy aids in the rehabilitation process following neurological injuries. As a training tool, the device provides a means to implement flexible, repeatable, and safe training methodologies.

Abhishek Gupta - One of the best experts on this subject based on the ideXlab platform.

  • Design of a haptic arm exoskeleton for training and rehabilitation
    IEEE ASME Transactions on Mechatronics, 2006
    Co-Authors: Abhishek Gupta, Marcia K. O'malley
    Abstract:

    A high-quality haptic interface is typically characterized by low Apparent Inertia and damping, high structural stiffness, minimal backlash, and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of space and weight limitations, workspace requirements, and the kinematic constraints placed on the device by the human arm. These constraints impose conflicting design requirements on the engineer attempting to design an arm exoskeleton. In this paper, the authors present a detailed review of the requirements and constraints that are involved in the design of a high-quality haptic arm exoskeleton. In this context, the design of a five-degree-of-freedom haptic arm exoskeleton for training and rehabilitation in virtual environments is presented. The device is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training. Motivation for such applications is based on findings that show robot-assisted physical therapy aids in the rehabilitation process following neurological injuries. As a training tool, the device provides a means to implement flexible, repeatable, and safe training methodologies.

  • design of a haptic arm exoskeleton for training and rehabilitation
    ASME 2004 International Mechanical Engineering Congress and Exposition, 2004
    Co-Authors: Abhishek Gupta, Marcia K Omalley
    Abstract:

    A high-quality haptic interface is typically characterized by low Apparent Inertia and damping, high structural stiffness, minimal backlash and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of additional parameters and constraints including space and weight limitations, workspace requirements and the kinematic constraints placed on the device by the human arm. In this context, we present the design of a five degree-of-freedom haptic arm exoskeleton for training and rehabilitation in virtual environments. The design of the device, including actuator and sensor selection, is discussed. Limitations of the device that result from the above selections are also presented. The device is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training.Copyright © 2004 by ASME

Perry Y. Li - One of the best experts on this subject based on the ideXlab platform.

  • Passive bilateral feedforward control of linear dynamically similar teleoperated manipulators
    IEEE Transactions on Robotics and Automation, 2003
    Co-Authors: Dongjun Lee, Perry Y. Li
    Abstract:

    Presents a passive bilateral feedforward control scheme for linear dynamically similar (LDS) teleoperated manipulators with kinematic scaling and power scaling. The proposed control law renders the teleoperator as a passive rigid mechanical tool with programmable Apparent Inertia to the human operator and the work environment by utilizing bilateral force feedforward and kinematic feedback control. The passivity of the closed-loop system is robust to force measurement inaccuracies and model uncertainty. Thus, interaction stability of the teleoperator with any passive environment is guaranteed. Coordination error and the overall motion aspects of teleoperation are controlled individually. The proposed control law is also applicable to general nonlinear robotic teleoperators if sufficiently high kinematic feedback gains are used. The proposed control schemes have been validated experimentally for both LDS and non-LDS systems.