9 research outputs found

    A Whole-Body Pose Taxonomy for Loco-Manipulation Tasks

    Full text link
    Exploiting interaction with the environment is a promising and powerful way to enhance stability of humanoid robots and robustness while executing locomotion and manipulation tasks. Recently some works have started to show advances in this direction considering humanoid locomotion with multi-contacts, but to be able to fully develop such abilities in a more autonomous way, we need to first understand and classify the variety of possible poses a humanoid robot can achieve to balance. To this end, we propose the adaptation of a successful idea widely used in the field of robot grasping to the field of humanoid balance with multi-contacts: a whole-body pose taxonomy classifying the set of whole-body robot configurations that use the environment to enhance stability. We have revised criteria of classification used to develop grasping taxonomies, focusing on structuring and simplifying the large number of possible poses the human body can adopt. We propose a taxonomy with 46 poses, containing three main categories, considering number and type of supports as well as possible transitions between poses. The taxonomy induces a classification of motion primitives based on the pose used for support, and a set of rules to store and generate new motions. We present preliminary results that apply known segmentation techniques to motion data from the KIT whole-body motion database. Using motion capture data with multi-contacts, we can identify support poses providing a segmentation that can distinguish between locomotion and manipulation parts of an action.Comment: 8 pages, 7 figures, 1 table with full page figure that appears in landscape page, 2015 IEEE/RSJ International Conference on Intelligent Robots and System

    Algorithm for the prediction of the reactive forces developed in the socket of transfemoral amputees

    Get PDF
    Based on a mathematical model of the human gait, a Matlab 2010a algorithm is presented to predict the reaction forces and moments in a particular point along the socket linked to the lower limb of a transfemoral amputee. The model takes the inertia developed due the swing of the limb during the gait into consideration. A validation of the results is made with the data obtained in a gait lab, and the model results are consistent with those obtained in the gait lab

    Analyzing Whole-Body Pose Transitions in Multi-Contact Motions

    Full text link
    When executing whole-body motions, humans are able to use a large variety of support poses which not only utilize the feet, but also hands, knees and elbows to enhance stability. While there are many works analyzing the transitions involved in walking, very few works analyze human motion where more complex supports occur. In this work, we analyze complex support pose transitions in human motion involving locomotion and manipulation tasks (loco-manipulation). We have applied a method for the detection of human support contacts from motion capture data to a large-scale dataset of loco-manipulation motions involving multi-contact supports, providing a semantic representation of them. Our results provide a statistical analysis of the used support poses, their transitions and the time spent in each of them. In addition, our data partially validates our taxonomy of whole-body support poses presented in our previous work. We believe that this work extends our understanding of human motion for humanoids, with a long-term objective of developing methods for autonomous multi-contact motion planning.Comment: 8 pages, IEEE-RAS International Conference on Humanoid Robots (Humanoids) 201

    Analyzing Whole-Body Pose Transitions in Multi-Contact Motions

    Get PDF
    Abstract-When executing whole-body motions, humans are able to use a large variety of support poses which not only utilize the feet, but also hands, knees and elbows to enhance stability. While there are many works analyzing the transitions involved in walking, very few works analyze human motion where more complex supports occur. In this work, we analyze complex support pose transitions in human motion involving locomotion and manipulation tasks (loco-manipulation). We have applied a method for the detection of human support contacts from motion capture data to a largescale dataset of loco-manipulation motions involving multicontact supports, providing a semantic representation of them. Our results provide a statistical analysis of the used support poses, their transitions and the time spent in each of them. In addition, our data partially validates our taxonomy of wholebody support poses presented in our previous work. We believe that this work extends our understanding of human motion for humanoids, with a long-term objective of developing methods for autonomous multi-contact motion planning

    Compliant Control of Multicontact and Center-of-Mass Behaviors in Humanoid Robots

    Full text link

    Desarrollo de un algoritmo computacional para la predicciĂłn de fuerzas y momentos en la interfaz socket-extensiĂłn femoral durante el ciclo completo de la marcha para amputados transfemorales

    Get PDF
    Resumen: Con el fin de predecir las fuerzas y momentos en la interface socket-extensiĂłn femoral de amputados transfemorales sin necesidad de procedimientos experimentales complejos o extensos en el tiempo, se propone un flujo para el modelado y simulaciĂłn de la marcha humana. La metodologĂ­a consiste en un modelo matemĂĄtico de la geometrĂ­a del cuerpo humano que puede generar las medidas antropomĂ©tricas bĂĄsicas necesarias para escalar un modelo mĂșsculo esquelĂ©tico modificado en Opensim. Un algoritmo es implementado para este modelo en el cual solo el peso, la altura, el gĂ©nero y la longitud del miembro residual son necesarios. El modelo escalado en Opensim es usado para calcular un anĂĄlisis de contacto articular a partir del cual las fuerzas musculares presentes en el modelo y las fuerzas y momentos resultantes en la interfaz socket-extensiĂłn femoral son obtenidas.Abstract: In order to predict the forces and moments in the interface socket-femoral extension of transfemoral amputees without complex or time consuming experimental setups, a frame work for the modelling and simulation of the biomechanics of the human gait is proposed. The methodology consists in a mathematical model of the human geometry that can generate the basic anthropometric measurements necessary to scale a custom made musculo squeletal Opensim model. An algorithm is implemented for this model in which only the weight, stature, gender and residual limb length are necessary. The scaled model in Opensim is used to perform a joint contact analysis from which the muscular forces present in the modeland the resultant forces and moments in the interface socket-femoral extension is extractedMaestrĂ­

    Behavioural robustness and the distributed mechanisms hypothesis

    Get PDF
    A current challenge in neuroscience and systems biology is to better understand properties that allow organisms to exhibit and sustain appropriate behaviours despite the effects of perturbations (behavioural robustness). There are still significant theoretical difficulties in this endeavour, mainly due to the context-dependent nature of the problem. Biological robustness, in general, is considered in the literature as a property that emerges from the internal structure of organisms, rather than being a dynamical phenomenon involving agent-internal controls, the organism body, and the environment. Our hypothesis is that the capacity for behavioural robustness is rooted in dynamical processes that are distributed between agent ‘brain’, body, and environment, rather than warranted exclusively by organisms’ internal mechanisms. Distribution is operationally defined here based on perturbation analyses. Evolutionary Robotics (ER) techniques are used here to construct four computational models to study behavioural robustness from a systemic perspective. Dynamical systems theory provides the conceptual framework for these investigations. The first model evolves situated agents in a goalseeking scenario in the presence of neural noise perturbations. Results suggest that evolution implicitly selects neural systems that are noise-resistant during coupling behaviour by concentrating search in regions of the fitness landscape that retain functionality for goal approaching. The second model evolves situated, dynamically limited agents exhibiting minimalcognitive behaviour (categorization task). Results indicate a small but significant tendency toward better performance under most types of perturbations by agents showing further cognitivebehavioural dependency on their environments. The third model evolves experience-dependent robust behaviour in embodied, one-legged walking agents. Evidence suggests that robustness is rooted in both internal and external dynamics, but robust motion emerges always from the systemin-coupling. The fourth model implements a historically dependent, mobile-object tracking task under sensorimotor perturbations. Results indicate two different modes of distribution, one in which inner controls necessarily depend on a set of specific environmental factors to exhibit behaviour, then these controls will be more vulnerable to perturbations on that set, and another for which these factors are equally sufficient for behaviours. Vulnerability to perturbations depends on the particular distribution. In contrast to most existing approaches to the study of robustness, this thesis argues that behavioural robustness is better understood in the context of agent-environment dynamical couplings, not in terms of internal mechanisms. Such couplings, however, are not always the full determinants of robustness. Challenges and limitations of our approach are also identified for future studies

    Generation of whole-body motion for humanoid robots with the complete dynamics

    Get PDF
    Cette thĂšse propose une solution au problĂšme de la gĂ©nĂ©ration de mouvements pour les robots humanoĂŻdes. Le cadre qui est proposĂ© dans cette thĂšse gĂ©nĂšre des mouvements corps-complet en utilisant la dynamique inverse avec l'espace des tĂąches et en satisfaisant toutes les contraintes de contact. La spĂ©cification des mouvements se fait Ă  travers objectifs dans l'espace des tĂąches et la grande redondance du systĂšme est gĂ©rĂ©e avec une pile de tĂąches oĂč les tĂąches moins prioritaires sont atteintes seulement si elles n'interfĂšrent pas avec celles de plus haute prioritĂ©. À cette fin, un QP hiĂ©rarchique est utilisĂ©, avec l'avantage d'ĂȘtre en mesure de prĂ©ciser tĂąches d'Ă©galitĂ© ou d'inĂ©galitĂ© Ă  tous les niveaux de la hiĂ©rarchie. La capacitĂ© de traiter plusieurs contacts non-coplanaires est montrĂ©e par des mouvements oĂč le robot s'assoit sur une chaise et monte une Ă©chelle. Le cadre gĂ©nĂ©rique de gĂ©nĂ©ration de mouvements est ensuite appliquĂ© Ă  des Ă©tudes de cas Ă  l'aide de HRP-2 et Romeo. Les mouvements complexes et similaires Ă  l'humain sont obtenus en utilisant l'imitation du mouvement humain oĂč le mouvement acquis passe par un processus cinĂ©matique et dynamique. Pour faire face Ă  la nature instantanĂ©e de la dynamique inverse, un gĂ©nĂ©rateur de cycle de marche est utilisĂ© comme entrĂ©e pour la pile de tĂąches qui effectue une correction locale de la position des pieds sur la base des points de contact permettant de marcher sur un terrain accidentĂ©. La vision stĂ©rĂ©o est Ă©galement introduite pour aider dans le processus de marche. Pour une rĂ©cupĂ©ration rapide d'Ă©quilibre, le capture point est utilisĂ© comme une tĂąche contrĂŽlĂ©e dans une rĂ©gion dĂ©sirĂ©e de l'espace. En outre, la gĂ©nĂ©ration de mouvements est prĂ©sentĂ©e pour CHIMP, qui a besoin d'un traitement particulier.This thesis aims at providing a solution to the problem of motion generation for humanoid robots. The proposed framework generates whole-body motion using the complete robot dynamics in the task space satisfying contact constraints. This approach is known as operational-space inverse-dynamics control. The specification of the movements is done through objectives in the task space, and the high redundancy of the system is handled with a prioritized stack of tasks where lower priority tasks are only achieved if they do not interfere with higher priority ones. To this end, a hierarchical quadratic program is used, with the advantage of being able to specify tasks as equalities or inequalities at any level of the hierarchy. Motions where the robot sits down in an armchair and climbs a ladder show the capability to handle multiple non-coplanar contacts. The generic motion generation framework is then applied to some case studies using HRP-2 and Romeo. Complex and human-like movements are achieved using human motion imitation where the acquired motion passes through a kinematic and then dynamic retargeting processes. To deal with the instantaneous nature of inverse dynamics, a walking pattern generator is used as an input for the stack of tasks which makes a local correction of the feet position based on the contact points allowing to walk on non-planar surfaces. Visual feedback is also introduced to aid in the walking process. Alternatively, for a fast balance recovery, the capture point is introduced in the framework as a task and it is controlled within a desired region of space. Also, motion generation is presented for CHIMP which is a robot that needs a particular treatment
    corecore