Contact force transitions in regrasp tasks of planar objects

This paper presents a simple and fast solution to the problem of finding the time variations of the forces that keep the object equilibrium when a finger is removed from a three contact point grasp or a finger is added to a two contact point grasp, assuming the existence of an external perturbation force (that can be the object weight itself). The procedure returns force set points for the control system of a manipulator device in a regrasping action. The approach was implemented and a numerical example is included in the paper to illustrate how it works

Grasp gaits for planar object manipulation

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (p. 97-98).by Susanna Richmond Leveroni.Ph.D

Deploying the NASA Valkyrie Humanoid for IED Response: An Initial Approach and Evaluation Summary

As part of a feasibility study, this paper shows the NASA Valkyrie humanoid robot performing an end-to-end improvised explosive device (IED) response task. To demonstrate and evaluate robot capabilities, sub-tasks highlight different locomotion, manipulation, and perception requirements: traversing uneven terrain, passing through a narrow passageway, opening a car door, retrieving a suspected IED, and securing the IED in a total containment vessel (TCV). For each sub-task, a description of the technical approach and the hidden challenges that were overcome during development are presented. The discussion of results, which explicitly includes existing limitations, is aimed at motivating continued research and development to enable practical deployment of humanoid robots for IED response. For instance, the data shows that operator pauses contribute to 50\% of the total completion time, which implies that further work is needed on user interfaces for increasing task completion efficiency.Comment: 2019 IEEE-RAS International Conference on Humanoid Robot

Modellbasierte automatisierte Greifplanung

Die vorliegende Arbeit beschreibt das Planungssystem Auto GRASP zur modellbasierten, automatisierten Planung von Greifoperationen bekannter Objekte im Arbeitsraum eines Roboters. Im Gegensatz zu existierenden Greifplanungssystemen werden bei der Planung sämtliche erforderlichen Nebenbedingungen des Greifvorgangs berücksichtigt. Das vorgestellte Greifverfahren beruht auf einer effizienten Zweiteilung der Planung in eine Offline- und in eine Online-Phase. Während der Offline-Phase erfolgt eine maximale Modelldatenaufbereitung der zu greifenden Objekte. Geometrische Filteroperationen, die eine Art Shape-Matching zwischen der Geometrie des eingesetzten Parallelbackengreifers und der zu greifenden Objekte durchführen, generieren Griffklassen eines Objektes. Hierbei beschreibt eine Griffklasse eine Menge von Greifkoordinatensystemen, die für den Greifer unter konstanter Orientierung kollisionsfrei erreichbar sind. Als Orientierungen werden repräsentative Greiferorientierungen bestimmt, die zu Formschluß mit der Handbasis des Greifers und damit zu einer Erhöhung der Griffstabilität führen. Sämtliche generierten Griffklassen werden unter Berücksichtigung diverser geometrischer Kriterien bewertet, die aus den Ergebnissen der Modelldatenaufbereitung folgen. Daneben werden objektspezifische Merkmale bestimmt, die in die Online-Phase der Planung von Greifoperationen einfließen. Für die Planung evtl. erforderlicher Umgreifoperationen werden ebenfalls im Rahmen der Modelldatenaufbereitung Plazierungsklassen sämtlicher Objekte der Modellwelt generiert und evaluiert. Eine Plazierungsklasse eines Objektes beschreibt eine Menge von stabilen Plazierungen auf einer horizontalen Ablagefläche, die einen gemeinsamen Kontaktbereich besitzen. Zur Bewertung der Stabilität einer Plazierungsklasse wird eine anschaulich zu interpretierende Evaluierungsfunktion eingeführt. Die Ergebnisse der Modelldatenaufbereitung fließen in die Online-Phase der Planung von Greifoperationen ein.Grasping has evolved from a somewhat marginal topic to an important field in robotics research. This increasing interest in grasping is partly due to the increasing importance of flexible assembly in industrial automation. The thesis describes the model based grasp planning system Auto GRASP for automatically grasping objects in a robot’s workspace. In contrast to existing grasp planning systems various constraints are taken into account required for a successful execution of a grasp operation. The computations performed by Auto GRASP are split into offline and online computations, with as much a priori knowledge as possible used in the offline phase. During the offline phase a geometric grasp planning is performed using the concept of symbolic grasps. Symbolic grasps are generated by filter operations performing a kind of shape matching between the geometry of the gripper and the objects to be grasped. To reduce computational costs, representative gripper orientations are determined for each symbolic grasp. The new concept of representative gripper orientations guarantees, that the gripper’s palm can achieve form closure with the objects to be grasped. Thus, higher stability is achieved to resist dynamic disturbance forces arising during the motion of the robot. For each representative gripper orientation collision free approach trajectories and grasp frames are calculated in a local xy-configuration space respective to the objects. The resulting sets of grasp frames define grasp classes that are evaluated taking into account several evaluation criteria. For the generation of regrasp sequences, placement classes of objects are generated and evaluated. Placement classes describe stable object placements on a horizontal plane

The Design Of A Community-Informed Socially Interactive Humanoid Robot And End-Effectors For Novel Edge-Rolling

This dissertation discusses my work in building an HRI platform called Quori and my once separate now integrated work on a manipulation method that can enable robots like Quori, or any more capable robot, to move large circular cylindrical objects. Quori is a novel, affordable, socially interactive humanoid robot platform for facilitating non-contact human-robot interaction (HRI) research. The design of the system is motivated by feedback sampled from the HRI research community. The overall design maintains a balance of affordability and functionality. Ten Quori platforms have been awarded to a diverse group of researchers from across the United States to facilitate HRI research to build a community database from a common platform. This dissertation concludes with a demonstration of Quori transporting a large cylinder for which Quori does not have the power to lift nor the range of motion to dexterously manipulate. Quori is able to achieve this otherwise insurmountable task through a novel robotic manipulation technique called robotic edge-rolling. Edge-rolling refers to transporting a cylindrical object by rolling on its circular edge, as human workers maneuver a gas cylinder on the ground for example. This robotic edge-rolling is achieved by controlling the object to roll on the bottom edge in contact with the ground, and to slide on the surface of the robot\u27s end-effector. It can thus be regarded as a form of robotic dexterous, in-hand manipulation with nonprehensile grasps. This work mainly addresses the problem of grasp planning for edge-rolling by studying how to design appropriately shaped end-effectors with zero internal mobility and how to find feasible grasps for stably rolling the object with the simple end-effectors

Grasp planning for object manipulation by an autonomous robot

L'évolution autonome d'un robot dans un environnement évolutif nécessite qu'il soit doté de capacités de perception, d'action et de décision suffisantes pour réaliser la tâche assignée. Une tâche essentielle en robotique est la manipulation d'objets et d'outils. Elle intervient non seulement pour un robot seul mais également dans des situations d'interaction avec un humain ou un autre robot quand il s’agit d’échanger des objets ou de les manipuler conjointement.\ud Cette thèse porte sur la planification de tâches de manipulation d'objets pour un robot autonome dans un environnement humain. Une architecture logicielle susceptible de résoudre ce type de problèmes au niveau géométrique est proposée. Généralement, une tâche de manipulation commence par une opération de saisie dont la qualité conditionne fortement la réussite de la tâche et pour laquelle nous proposons un planificateur basé sur les propriétés inertielles de l'objet et une décomposition en éléments quasi-convexes tout en prenant en compte les contraintes imposées par le système mobile complet dans un environnement donné.\ud Les résultats sont validés en simulation et sur le robot sur la base d’une extension des outils de planification développés au LAAS-CNRS. Le modèle géométrique 3D de l’objet peut être connu a priori ou bien acquis en ligne. Des expérimentations menées sur un robot manipulateur mobile équipé d'une pince à trois points de contacts, de capteurs de force et d'une paire de caméras stéréoscopiques ont montré la validité de l'approche.\ud The autonomous robot performance in a dynamic environment requires advanced perception, action and decision capabilities. Interaction with the environment plays a key role for a robot and it is well illustrated in object and/or tool manipulation. Interaction with humans or others robots can consist in object exchanges.\ud This thesis deals with object manipulation planning by an autonomous robot in human environments. A software architecture is proposed that is capable to solve such problems at the geometrical level. In general, a manipulation task starts by a grasp operation which quality influences strongly the success of the overall task. We propose a planner based on object inertial properties and an approximate convex decomposition. The whole mobile system taken into account in the planning process.\ud The planner has been completely implemented as an extension of the planning tools developed at LAAS-CNRS. Its results have been tested in simulation and on a robotic platform. Object models may be known a priori or acquired on-line. Experiments have been carried out with a mobile manipulator equipped with a three fingers gripper, a wrist force sensor and a stereo camera system in order to validate the approach.\ud \ud \u

Modeling and control of an anthropomorphic robotic hand

Mención Europea en el título de doctorThis thesis presents methods and tools for enabling the successful use of robotic hands. For highly dexterous and/or anthropomorphic robotic hands, these methods have to share some common goals, such as overcoming the potential complexity of the mechanical design and the ability of performing accurate tasks with low and efficient computational cost. A prerequisite for dexterity is to increase the workspace of the robotic hand. For this purpose, the robotic hand must be considered as a single multibody system. Solving the inverse kinematics problem of the whole robotic hand is an arduous task due to the high number of degrees of freedom involved and the possible mechanical limitations, singularities and other possible constraints. The redundancy has proven to be of a great usefulness for dealing with potential constraints. To be able to exploit the redundancy for dealing with constraints, the adopted method for solving the inverse kinematics must be robust and extendable. Obviously, addressing such complex problem, the method will certainly be computationally heavy. Thus, one of the aims of this thesis is to resolve the inverse kinematics problem of the whole robotic hand under constraints, taking into account the computational cost. To this end, this thesis extends and reduces the most recent Selectively Damped Least Squares method which is based on the computation of all singular values, to deal with constraints with a minimum computational cost. New estimation algorithm of singular values and their corresponding singular vectors is proposed to reduce the computational cost. The reduced extended selectively damped least squares method is simulated and experimentally evaluated using an anthropomorphic robotic hand as a test bed. On the other hand, dexterity depends not only on the accuracy of the position control, but also on the exerted forces. The tendon driven modern robotic hands, like the one used in this work, are strongly nonlinear dynamic systems, where motions and forces are transmitted remotely to the finger joints. The problem of modeling and control of position and force simultaneously at low level control is then considered. A new hybrid control structure based on the succession of two sliding mode controllers is proposed. The force is controlled by its own controller which does not need a contact model. The performance of the proposed controller is evaluated by performing the force control directly using the force sensor information of the fingertip, and indirectly using the torque control of the actuator. Finally, we expect that the applications of the methods presented in this thesis can be extended to cover different issues and research fields and in particular they can be used in a variety of algorithm that require the estimation of singular values.This work was partially supported by the European project HANDLE, FP7-231640, and by the Spanish ministry MICINN through FPI scholarship within the project DPI-2005-04302.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Anis Sahbani.- Secretario: Fares Jawad Moh D Abu-Dakka.- Vocal: Claudio Ross

Physics-, social-, and capability- based reasoning for robotic manipulation

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 124-128).Robots that can function in human-centric domains have the potential to help humans with the chores of everyday life. Moreover, dexterous robots with the ability to reason about the maneuvers they execute for manipulation tasks can function more autonomously and intelligently. This thesis outlines the development of a reasoning architecture that uses physics-, social-, and agent capability-based knowledge to generate manipulation strategies that a dexterous robot can implement in the physical world. The reasoning system learns object affordances through a combination of observations from human interactions, explicit rules and constraints imposed on the system, and hardcoded physics-based logic. Observations from humans performing manipulation tasks are also used to develop a unique manipulation repertoire suitable for the robot. The system then uses Bayesian Networks to probabilistically determine the best manipulation strategies for the robot to execute on new objects. The robot leverages this knowledge during experimental trials where manipulation strategies suggested by the reasoning architecture are shown to perform well in new manipulation environments.by Kenton J. Williams.S.M

From Deployments Of Elder Care Service Robots To The Design Of Affordable Low-Complexity End-Effectors And Novel Manipulation Techniques

This thesis proposes an investigation on both behavioral and technical aspects of human-robot interaction (HRI) in elder care settings, in view of an affordable platform capable of executing desired tasks. The behavioral investigation combines a qualitative study with focus groups and surveys from not only the elders’ standpoint, but also from the standpoint of healthcare professionals to investigate suitable tasks to be accomplished by a service robot in such environments. Through multiple deployments of various robot embodiments at actual elder care facilities (such as at a low-income Supportive Apartment Living, SAL, and Program of All-Inclusive Care, PACE Centers) and interaction with older adults, design guidelines are developed to improve on both interaction and usability aspects. This need assessment informed the technical investigation of this work, where we initially propose picking and placing objects using end-effectors without internal mobility (or zero degrees-of-freedom, DOF), considering both quasi-static (tipping and regrasping as in-hand manipulation) and dynamic approaches. Maximizing grasping versatility by allowing robots to grasp multiple objects sequentially using a single end-effector and actuator is also proposed. These novel manipulation techniques and end-effector designs focus on minimizing robot hardware usage and cost, while still performing complex tasks and complying with safety constraints imposed by the elder care facilities