Marche inspirée de l'humain pour le robot Romeo

The objective of this thesis is to develop a method for generating various human-inspired walking movements adapted to the Romeo robotic platform. The desired walking gait must retain the essential characteristics of human gait (trajectory of the centre of mass, foot and arm movements) while maintaining a dynamic balance of the robot.A bibliographical study of human movements is used to establish the essential characteristics of walking that are to be preserved. These characteristics are then adapted to the constraints of the robotic platform (limits in torque, position, speed and acceleration of the robot joints). A periodic gait motion is generated using the Essential Model and the previously defined characteristics. Finally, start and stop walking motions corresponding to the chosen periodic gait are generated. The resulting complete walking motion is tested in simulation and on the physical platform.L'objectif de cette thèse est de développer une méthode de génération de mouvements de marche inspirés de l'humain et adaptés à la plateforme robotique Romeo. La marche recherchée reprend les caractéristiques essentielles de la marche humaine (trajectoire du centre de masse, mouvements du pied libre et des bras) tout en conservant un équilibre dynamique du robot.Une étude bibliographique des mouvements humains permet d'établir les caractéristiques essentielles de la marche qui doivent être conservées. Ces caractéristiques sont ensuite adaptées aux capacités de la plateforme robotique (limites en couple, position, vitesse et accélération des articulations). Un mouvement de marche périodique est généré grâce à l'utilisation du Modèle Essentiel et des caractéristiques définies précédemment. Ces mouvements de marche périodiques sont ensuite enrichis d'une phase de démarrage et d'une phase d'arrêt. La marche complète ainsi obtenue est testée en simulation et sur la plateforme physique

Self-synchronization and Self-stabilization of Walking Gaits Modeled by the 3D LIP Model

International audienc

An essential model for generating walking motions for humanoid robots

conférence invitéeInternational audienc

Self-Synchronization and Self-Stabilization of Walking Gaits Modeled by the Three-Dimensional LIP Model

International audienceThe linear inverted pendulum model is often used to study walking gaits, but the transition from one step to the following step is often neglected, whereas it is really important for the walking stability. This letter studies different landing positions of the swing foot, and different conditions to switch the stance leg, based on time or on the configuration of the robot. It is shown that self-synchronization of the motion in sagittal and frontal planes is dependent on different switching conditions. Neither self-synchronization nor self-stabilization is observed when the stance leg switching is based on time or when both the step length and width are fixed. On the other hand, self-synchronization can be obtained when the switching condition of the stance leg is based on a linear combination of the positions of the center of mass (CoM) along the sagittal and frontal axes. Moreover, self-stabilization can be obtained when the velocity of the CoM in the sagittal plane is taken into account. Index Terms-Humanoid and bipedal locomotion, passive walking , dynamic stability

An essential model for generating walking motions for humanoid robots

International audienceThe modeling of humanoid robots with many degrees-of-freedom (DoF) can be done via the complete dynamic model. However, the complexity of the model can hide the essential factor of the walking, i.e. the equilibrium of the robot. One alternative is to simplify the model by neglecting some dynamical effects like in the 3D Linear Inverted Pendulum (LIP) model. Nonetheless, the assumption that the ZMP will be at the base of the pendulum is not ensured and the resulting walking gaits can make the Zero Moment Point (ZMP) evolves outside of the convex hull of support when they are replicated by the complete model of any humanoid robot. The objective of this paper is to propose a new model for walking that has the same dimensions as the 3D LIP model but considers the complete dynamics of the humanoid. The proposed model is called essential model and it can be written based on the internal states of the robot and/or external information, thereby generating models for different purposes. The main advantage of the essential model is that it allows to generate walking gaits that ensure that the Zero Moment Point (ZMP) is kept in a desired position or it follows a desired path while the gait is performed. Furthermore, impacts of the swing foot with the ground can be considered to compute periodic walking gaits. In order to show the advantages of the proposed model, numerical studies are performed to design periodic walking gaits for the humanoid robot ROMEO