Cette thèse traite du problème de localisation et contrôle de robots humanoïdes par rapport à leur environnement, tel qu'observé par ses capteurs embarqués. Le SLAM visuel dense, consistant en l'estimation simultanée d'une carte 3D de l'environnement et de la position du robot dans cette carte est exploité pour étendre et robustifier les méthodes de planification contrôle multi-contact. Celles-ci consistent à établir et exploiter des contacts robot-environnement pour accomplir des tâches de locomotion et manipulation. Des incertitudes sur la posture initiale du robot, ainsi que des perturbations causées par une modélisation inadéquate des contacts, ainsi que des perturbations externes oblige à la prise en compte de l'état du robot et son environnement. Une méthode de calibration corps-complet est également proposée, afin d'obtenir une connaissance fiable de la chaîne cinématique du robot, nécessaire pour réaliser de telles tâches. Finalement, une méthode de marche basée sur de la commande prédictive de modèles est robustifiée par la prise en compte de large perturbations, permettant d'ajuster les trajectoires de pied et du centre de masse afin de garantir sa stabilité, tout en accomplissant les objectifs désirés. Les méthodes proposées sont illustrées et validées par de multiples expérimentations sur les robots humanoïdes HRP-2Kai et HRP-4. / This thesis deals with the problem of localizing and controlling humanoid robots with respect to its environment, as observed by its on-board sensors. Dense visual SLAM, consisting in the simultaneous estimation of a 3D map of the environment and of the robot localization within that maps is exploited to extend and robustify multi-contact planning and control. Establishing and exploiting robot-environment contacts allows the accomplishment of both locomotion and manipulation tasks. Uncertainties in the initial robot posture, and perturbations arising from improper contact-modelling and external causes are accounted for by observing the state of the robot and its environment. A whole-body calibration method is also proposed, so that robust knowledge of the robot's kinematic structure is known, a prerequisite to all robot-environment interaction tasks. Finally, a walking method based on model predictive control is robustified by taking into account large perturbations, and adjusting the footstep and center-of-mass trajectories accordingly to guarantee stability while accomplishing desired objectives.Several experiments on an HRP-2Kai and an HRP-4 humanoid robots are presented and discussed to illustrate and validate each of the proposed methods.

This paper will present an online approach for friction approximation to be utilized in con- cert with whole body control on humanoid robots. This approach allows humanoid robots with ankle mounted force-torque sensors to extrapolate information about the friction constraints at the hands during multi-contact poses without the addition of hardware to the platform. This is achieved by utilizing disturbance detection as a method of monitoring active forces at a single external point and deriving available friction force at said contact point in accordance with Coulomb's Law of Friction. First, the rigid body dynamics and required compliant humanoid model optimization are established which allow incorporation of friction constraints. These friction constraints are then informed by monitoring of external forces, which can be used as an indicator of slip based on tangential force. In practice, the robot with operational multi-contact whole body control is navigated to the desired contact surface and normal force only contact is initiated. Using an iterative coefficient estimation based on the achieved system forces, the robot tests the boundaries of its operable force range by inducing slip. Slip detection is utilized as the basis for coefficient estimation, which allows the robot to further understand its environment and apply appropriate forces to its contact points. This approach was implemented on a simple 3 link model to verify expected performance, and then on both the simulated model of Virginia Tech's ESCHER robot and in practice on the actual ESCHER platform. The proposed approach was able to achieve estimation of slip parameters, based largely on time spent measuring, actual friction coefficient, and the available contact force. Though the performance of the proposed approach is dependent on a number of variables, it was able to provide an operational parameter for the robot's whole body controller, allowing expansion of the support region without risking multi-contact slip. / Master of Science / This paper presents an approach for humanoid robots to use their hands to approximate the friction parameters of contact surfaces without prior knowledge of those parameters. This is accomplished as part of the robot’s control system and integrated into its balancing and movement operating system so that it may determine these parameters without ceasing operation. The proposed approach relies on the force sensors typically embedded in the ankles of bipedal robots as its sole force input, so no additional hardware need be added to the robot in order to employ this functionality. Once placed in contact, the robot is able to approximate the forces at its hand with these sensors, and use those approximate values as the basis for estimating the static friction coefficient of the system, in accordance with Coulomb’s Law of Friction. The robot’s onboard controller is able to utilize this information to ensure that it does not overestimate the available force that may be applied at the contact point, using prior knowledge of the robot model’s range of motion. In practice, the robot with this functionality is navigated to the desired contact surface and a hand contact that does not risk slip is initiated. Using an iterative coefficient estimation based on the achieved system forces, the robot tests the boundaries of its operable force range by inducing slip. Slip detection is utilized as the basis for coefficient estimation, which allows the robot to further understand its environment and apply appropriate forces to its contact points. This approach was implemented on a simple 3 link robot model to verify expected performance, and then on both the simulated model of Virginia Tech’s ESCHER robot and in practice on the actual ESCHER platform. The proposed approach was able to achieve estimation of slip parameters, based largely on time spent measuring, actual friction coefficient, and the available contact force. Though the performance of the proposed approach is dependent on a number of variables, it was able to provide an operational parameter for the robot’s whole body controller, allowing expansion of the support region without risking multi-contact slip.

Although humanoid robots are being designed to assist people in various tasks, there remain gaps in our understanding of the perceptions that humanoid faces evoke in the user. Understanding user perceptions would help design robots that are better suited for the target user group. Younger and older adults’ preferences for robot appearance were assessed out of three levels of human-likeness. In general, people perceived a mixed human-robot appearance less favorably compared to highly human and highly robotic appearances. Additionally the nature of task also influenced people’s overall perceptions of robots. Robots were most positively evaluated for assistance with chores and less positively for personal care and decision-making. Moreover, task and robot humanness had an interactive effect on people’s likability, trust, and perceived usefulness toward robots. Age-related differences in preferences of robot humanness were also observed. Older adults showed a higher inclination toward human-looking appearance of robots whereas younger adults’ preferences were more distributed across the levels of humanness. An appearance with mixed human-robot features was more likely to be rejected by older adults than by younger adults, and the difference was most striking for a decision-making task. Besides the humanness of the robot face, perceptions of robot appearances were also influenced by factors such as robot gender, specific facial features/aesthetics, expressiveness, perceived personality, and perceived capability. Future studies should measure the relative weight of these different factors in the formation of perceptions, both at a global level and at a task-specific level.

Le travail présenté dans cette thèse est divisé en deux parties. Dans la première partie, un modèle pour la représentation unifiée de problèmes d'optimisation numérique est proposé. Ce modèle permet de définir un problème d'optimisation indépendamment de la stratégie utilisée pour le résoudre. Cette représentation unifiée est particulièrement appréciable en robotique où une solution analytique des problèmes est rarement possible. La seconde partie traite de l'exécution de mouvements complexes asservis sur un robot humanoïde. Lors de la locomotion d'un tel système, les glissements des points de contact entraînent une dérive qu'il est nécessaire de corriger. Nous proposons ici un modèle permettant d'asservir une tâche de locomotion sur un capteur externe afin de compenser les erreurs d'exécution des mouvements. Un modèle est également proposé permettant de représenter des séquences de tâches de locomotion et de manipulation asservies. Enfin, une méthodologie pour le développement d'applications robotiques complexes est établie. Les stratégies proposées dans le cadre de cette thèse ont été validées sur la plate-forme expérimentale HRP-2. / The presented work is divided into two parts. In the first one, an unified computer representation for numerical optimization problems is proposed. This model allows to define problems independently from the algorithm used to solve it. This unified model is particularly interesting in robotics where exact solutions are difficult to find. The second part is dealing with complex trajectory execution on humanoid robots with sensor feedback. When a biped robots walks, contact points often slip producing a drift which is necessary to compensate. We propose here a closed-loop control scheme allowing the use of sensor feedback to cancel execution errors. To finish, a method for the the development of complex robotics application is detailed. This thesis contributions have been implemented on the HRP-2 humanoid robot.

Un robot humanoïde est un système polyarticulé complexe dont la cinématique et la dynamique sont gouvernées par des équations non linéaires. Trouver des postures viables qui minimisent une tâche objectif tout en satisfaisant un ensemble de contraintes (intrinsèques ou extrinsèques) est un problème central pour la planification de mouvement robotique et est une fonctionnalité importante de tout logiciel de robotique. Le générateur de posture (PG) a pour rôle de trouver une posture viable en formulant puis résolvant un problème d’optimisation non linéaire. Nous étendons l’état de l’art en proposant de nouvelles formulations et méthodes de résolution de problèmes de génération de postures. Nous enrichissons la formulation de contraintes de contact par ajout de variables au problème d’optimisation, ce qui permet au solveur de décider automatiquement de la zone d’intersection entre deux polygones en contact ou encore de décider du lieu de contact sur une surface non plane. Nous présentons une reformulation du PG qui gère nativement les variétés non Euclidiennes et nous permet de formuler des problèmes mathématiques plus élégants et efficaces. Pour résoudre de tels problèmes, nous avons développé un solveur non linéaire par SQP qui supporte nativement les variables sur variétés. Ainsi, nous avons une meilleure maîtrise de notre solveur et pouvons le spécialiser pour la résolution de problèmes de robotique. / Humanoid robots are complex poly-articulated structures whose kinematics and dynamics are governed by nonlinear equations. Finding viable postures to realize set-point task objectives under a set of constraints (intrinsic and extrinsic limitations) is a key issue in the planning of robot motion and an important feature of any robotics framework. It is handled by the so called posture generator (PG) that consists in formalizing the viable posture as the solution to a nonlinear optimization problem. We present several extensions to the state-of-the-art by exploring new formulations and resolution methods for the posture generation problems. We reformulate the notion of contact constraints by adding variables to enrich our optimization problem and allow the solver to decide on the shape of the intersection of contact polygons or of the location of a contact point on a non-flat surface. We present a reformulation of the PG problem that encompasses non-Euclidean manifolds natively for a more elegant and efficient mathematical formulation of the problems. To solve such problems, we decided to implement a new SQP solver that is most suited to non-Euclidean manifolds structural objects. By doing so, we have a better mastering in the way to tune and specialize our solver for robotics problems.

With this study, the authors wish to highlight the way artificial intelligence, as a new form of media technology, seems to be ascribed gender, both in fiction and reality. These, by humans artificially developed beings, would not need to be gendered, but still are. Given these beings are human made and new phenomenas, an opportunity of preventing boundaries considering gender, class and etnicity to be reproduced would be possible and in favour. By analysing the Alex Garland 2015 film Ex Machina, the authors wish to discuss how and why the artificial intelligence becomes gendered, particularly feminised, and what this means from a wider perspective concerning the way we look at this new technlology not yet fully introduced in real life. By using post- and transhuman theory mixed with feminist theories such as Judith Butlers theory of perfomativity, Donna Haraways posthuman feminist theory and Laura Mulveys theory of The Male Gaze, this study results in a qualitative text analysis. The methodic tools used in this study contains elements from visual text methods and therefor also semiotics.   The authors reach to the conclusion that the depiction of artificial intelligence in the film Ex Machina (2015) reproduces stereotypic feminine gender acts and even intensifies these. When these ways of presenting new and futuristic technology seems to appear in ficiton, an assumption can be made that they origin from existing and deep gender acts in the western society. Researchers, such as Donna Haraway, wishes for these strong boundaries in gender, class and etnicity to not be reproduced in new technology, but in the fictional case of the film Ex Machina (2015), this wish has unfortunately not been fullfilled. If society would be able to rethink the sharp boundaries between nature and technology and succeed with this ontological change in the way we look at humanity, it would hopefully be easier to approach the new technology with an open mind. Perhaps then the reproduction of gender stereotypes in this new technology would cease in fiction, but also in reality.

Bien que la pleine autonomie dans des environnements inconnus soit encore loin, les architectures de contrôle partagé où l'humain et un contrôleur autonome travaillent ensemble pour atteindre un objectif commun peuvent constituer un « terrain intermédiaire » pragmatique. Dans cette thèse, nous avons abordé les différents problèmes des algorithmes de contrôle partagé pour les applications de saisie et de manipulation. En particulier, le travail s'inscrit dans le projet H2020 Romans dont l'objectif est d'automatiser le tri et la ségrégation des déchets nucléaires en développant des architectures de contrôle partagées permettant à un opérateur humain de manipuler facilement les objets d'intérêt. La thèse propose des architectures de contrôle partagé différentes pour manipulation à double bras avec un équilibre opérateur / autonomie différent en fonction de la tâche à accomplir. Au lieu de travailler uniquement sur le contrôle instantané du manipulateur, nous proposons des architectures qui prennent en compte automatiquement les tâches de pré-saisie et de post-saisie permettant à l'opérateur de se concentrer uniquement sur la tâche à accomplir. La thèse propose également une architecture de contrôle partagée pour contrôler un humanoïde à deux bras où l'utilisateur est informé de la stabilité de l'humanoïde grâce à un retour haptique. En plus, un nouvel algorithme d'équilibrage permettant un contrôle optimal de l'humanoïde lors de l'interaction avec l'environnement est également proposé. / While full autonomy in unknown environments is still in far reach, shared-control architectures where the human and an autonomous controller work together to achieve a common objective may be a pragmatic "middle-ground". In this thesis, we have tackled the different issues of shared-control architectures for grasping and sorting applications. In particular, the work is framed in the H2020 RoMaNS project whose goal is to automatize the sort and segregation of nuclear waste by developing shared control architectures allowing a human operator to easily manipulate the objects of interest. The thesis proposes several shared-control architectures for dual-arm manipulation with different operator/autonomy balance depending on the task at hand. While most of the approaches provide an instantaneous interface, we also propose architectures which automatically account for the pre-grasp and post-grasp trajectories allowing the operator to focus only on the task at hand (ex., grasping). The thesis also proposes a shared control architecture for controlling a force-controlled humanoid robot in which the user is informed about the stability of the humanoid through haptic feedback. A new balancing algorithm allowing for the optimal control of the humanoid under high interaction forces is also proposed.

Η παρούσα διπλωματική εργασία πραγματεύεται την ανάπτυξη μιας εφαρμογής επεξεργασίας και δημιουργίας 3D ανθρωποειδών για χρήση σε Δικτυακά Εικονικά Περιβάλλοντα. Η εφαρμογή επιτρέπει την μοντελοποιηση και σύνθεση ενός 3D ανθρωποειδούς χρησιμοποιώντας έναν αριθμό απο έτοιμα αντικείμενα. Η ανάπτυξη της εφαρμογής έγινε με γλώσσα Java στην πλατφόρμα Eclipse, ενώ οι 3D τεχνολογίες που υποστηρίζει είναι οι VRML / X3D και H-Anim. / The main objective of this work is the development of a Java-based application for the creation and editing of 3d Humanoid Avatars intended to be used specifically for Networked Virtual Environments. The application supports the modelling and synthesis of a 3D avatar using already existing primitives. The tool was developed using the Eclipse platform, and the supported 3D technologies are VRML / X3D and the H-Anim standard.

Les robots humanoïdes ont toujours fasciné car leur potentiel d’application est considérable. En effet, si un robot avait les mêmes caractéristiques sensori-motrices et morphologiques qu’un homme, il pourrait théoriquement réaliser les mêmes tâches. Cependant, un premier obstacle au développement de ces robots est la stabilité d’une posture bipède. Lors d’une marche bipède, la marge d’erreur est très faible et les décisions doivent être prises rapidement avec une information souvent incomplète et incertaine. L’incertitude a de multiples sources comme des capteurs imparfaits, un modèle simplifié du monde ou encore une mécanique imprécise.Dans cette thèse, nous partons d’un contrôle de la marche par gestion des points d’appuis. L’idée est d’affiner le choix des points d’appuis en intégrant dans notre modèle les incertitudes que l’on vient d’évoquer. Pour cela, nous allons utiliser un modèle probabiliste Bayésien. A l’aide d’une distribution de probabilité, on peut exprimer simultanément une estimation, et l’incertitude associée à celle-ci. Le cadre théorique des probabilités Bayésiennes permet de définir les variables, et de les intégrer de manière rigoureuse dans un modèle global.Un autre avantage de ce modèle probabiliste est que notre objectif est aussi décrit sous la forme d’une distribution de probabilité. Il est donc possible de s’en servir pour exprimer à la fois un objectif déterministe, et une tolérance autour de celui-ci. Cela va nous permettre de fusionner facilement plusieurs objectifs et de les adapter automatiquement en fonction des contraintes extérieures. De plus, la sortie du modèle étant elle aussi une distribution de probabilité, ce type de modèle s’intègre parfaitement dans un cadre hiérarchique : l’entrée du modèle vient du niveau au-dessus et sa sortie est donnée en objectif niveau en dessous.Dans ce travail, nous allons d’abord explorer une technique de maintien de l’équilibre et la comparer aux résultats d’une expérience préliminaire sur l’homme. Nous allons ensuite étendre cette technique pour créer une stratégie de marche. Autour de cette stratégie, nous allons construire un modèle probabiliste Bayésien. Ce modèle sera finalement implémenté en simulation pour pouvoir quantifier son intérêt dans les différentes situations évoquées plus haut : intégration des incertitudes, fusion d’objectifs et hiérarchie. / Humanoid robots have always fascinated due to the vast possibilities they encompass.Indeed, a robot with the same sensorimotor features as a human could theoretically carry out the same tasks. However, a first obstacle in the development of these robots is the stability of a bipedal gait. Bipedal walkers are inherently unstable systems experiencing highly dynamic and uncertain situations. Uncertainty arises from many sources, including intrinsic limitations of a particular model of the world, the noise and perceptual limitations in a robot's sensor measurements, and the internal mechanical imperfection of the system.In this thesis, we focus on foot placement to control the position and velocity of the body's center of mass. We start from a deterministic strategy, and develop a probabilistic strategy around it that includes uncertainties. A probability distribution can express simultaneously an estimation of a variable, and the uncertainty associated. We use a Bayesian model to define relevant variables and integrate them in the global frame.Another benefit of this model is that our objective is also represented as a probability distribution. It can be used to express both a deterministic objective and the tolerance around it. Using this representation one can easily combine multiple objectives and adapt them to external constraints. Moreover, the output of the model is also a probabilistic distribution which fits well in a hierarchical context: the input comes from the level above and the output is given as objective to the lower level.In this work, we will review multiple ways to keep balance and compare them to the results of a preliminary experiment done with humans. We will then extend one strategy to walking using foot placement to keep balance. Finally, we will develop a probabilistic model around that strategy and test it in simulation to measure its benefits in different contexts : integrating uncertainties, fusing multiple objectives and hierarchy.

No description available.