Retour au site du LAAS-CNRS

Laboratoire d’analyse et d’architecture des systèmes

Publications de l'équipe gepetto

Choisir la langue : FR | EN

402documents trouvés

18101
01/10/2018

An overview of humanoid robots technologies

O.STASSE, T.FLAYOLS

GEPETTO

Ouvrage (contribution) : Biomechanics of Anthropomorphic Systems, Springer, N°ISBN 978-3-319-93870-7, Octobre 2018 , N° 18101

Lien : https://hal.laas.fr/hal-01759061

Diffusable

Plus d'informations

Abstract

Humanoid robots are challenging mechatronics structures with several interesting features. Choosing a humanoid robot to develop applications or pursue research in a given direction might be difficult due to the strong interdependence of the technical aspects. This paper aims at giving a general description of this interdependence and highlight the lessons learned from the impressive works conducted in the past decade. The reader will find in the annex a table synthesizing the characteristics of the most relevant humanoid robots. Without focusing on a specific application we consider two main classes of humanoid robots: the ones dedicated to industrial application and the ones dedicated to human-robot interaction. The technical aspects are described in a way which illustrates the humanoid robots bridging the gap between these two classes. Finally this paper tries to make a synthesis on recent technological developments 1. 1 Mechanical structure 1.1 General design principal Humanoid robots are complex mechatronic systems. As such, it is necessary to consider the the mechanical structure, the computational system and the algorithms as a whole and for a given application. The robot's size, weight and strength are important factors when designing its structure. Let us consider two general classes of applications: physical performances while doing motion generation and validation of biological and/or cognitive models. The ATLAS robot from Boston Dynamics is an example of the first category, while the Kenshiro robot [45] from Tokyo University is an example of the second category

144064
18021
01/10/2018

Historical Perspective of Humanoid Robot Research in Europe

Y.AOUSTIN, C.CHEVALLEREAU, J.P.LAUMOND

LS2N, GEPETTO

Ouvrage (contribution) : Humanoid Robotics: A Reference, Springer, N°ISBN 978-94-007-6045-5, Octobre 2018 , N° 18021

Lien : https://hal.archives-ouvertes.fr/hal-01697135

Diffusable

142457
17069
29/07/2018

Implementation, Identification and Control of an Efficient Electric Actuator for Humanoid Robots

F.FORGET, K.GIRAUD ESCLASSE, R.GELIN, N.MANSARD, O.STASSE

GEPETTO, Aldebaran

Manifestation avec acte : International Conference on Informatics in Control, Automation and Robotics ( ICINCO ) 2018 du 29 juillet au 31 juillet 2018, Porto (Portugal), Juillet 2018, 8p. , N° 17069

Lien : https://hal.archives-ouvertes.fr/hal-01494676

Diffusable

Plus d'informations

Abstract

Autonomous robots such as legged robots and mobile manipulators imply new challenges in the design and the control of their actuators. In particular, it is desirable that the actuators are back-drivable, efficient (low friction) and compact. In this paper, we report the complete implementation of an advanced actuator based on screw, nut and cable. This actuator has been chosen for the humanoid robot Romeo. A similar model of the actuator has been used to control the humanoid robot Valkyrie. We expose the design of this actuator and present its Lagrangian model. The actuator being flexible, we propose a two-layer optimal control solver based on Differential Dynamical Programming. The actuator design, model identification and control is validated on a full actuator mounted in a work bench. The results show that this type of actuation is very suitable for legged robots and is a good candidate to replace strain wave gears.

143712
18135
20/07/2018

Should mobile robots have a head ? -A rationale based on behavior, automatic control and signal processing

F.BAILLY, E.POUYDEBAT, B.WATIER, V.BELS, P.SOUERES

GEPETTO, MECADEV, ISYEB

Manifestation avec acte : International Conference on Biomimetic and Biohybrid Systems ( Living Machines ) 2018 du 17 juillet au 20 juillet 2018, Paris (France), Juillet 2018, 12p. , N° 18135

Lien : https://hal.archives-ouvertes.fr/hal-01803968

Diffusable

Plus d'informations

Abstract

This paper presents an interdisciplinary study of the role of the head in multisensory integration and motor-control organization for the production of voluntary spatial actions. It combines elements from biology and engineering. First, morphological and behavioral characteristics of animals able to perform voluntary spatial actions through evolution are examined. The complexity of state-space representation and observation of multi-joint mobile robots is then described in the context of automatic control, and perception-related characteristics brought by the presence of a head are presented from the perspective of signal processing. Finally, the role of the head in locomotion and manipulation for animals and robots is discussed, paving the way for future robot design.

143715
18124
30/06/2018

Analytical Derivatives of Rigid Body Dynamics Algorithms

J.CARPENTIER, N.MANSARD

GEPETTO

Manifestation avec acte : Robotics Science and Systems ( RSS ) 2018 du 26 juin au 30 juin 2018, Pittsburg (USA), Juin 2018, 10p. , N° 18124

Lien : https://hal.laas.fr/hal-01790971

Diffusable

Plus d'informations

Abstract

Rigid body dynamics is a well-established methodology in robotics. It can be exploited to exhibit the analytic form of kinematic and dynamic functions of the robot model. Two major algorithms, namely the recursive Newton-Euler algorithm (RNEA) and the articulated body algorithm (ABA), have been proposed so far to compute inverse dynamics and forward dynamics in a few microseconds. However, computing their derivatives remains a costly process, either using finite differences (costly and approximate) or automatic differentiation (difficult to implement and suboptimal). As computing the derivatives becomes an important issue (in optimal control, estimation, co-design or reinforcement learning), we propose in this paper new algorithms to efficiently compute them using closed-form formulations. We first explicitly differentiate RNEA, using the chain rule and adequate algebraic differentiation of spatial algebra. Then, using properties about the derivative of function composition, we show that the same algorithm can also be used to compute the derivatives of the forward dynamics with marginal additional cost. To this end, we finally introduce a new algorithm to compute the inverse of the joint-space inertia matrix, without explicitly computing the matrix itself. The algorithms have been implemented in our open-source C++ framework called Pinocchio. The reported benchmarks, based on several robot models, display computational costs varying between 3 microseconds (for a 7-dof arm) up to 17 microseconds (for a 36-dof humanoid), i.e. outperforms state-of-the-art results.

143902
18138
26/06/2018

Handling implicit and explicit constraints in manipulation planning

J.MIRABEL, F.LAMIRAUX

GEPETTO

Manifestation avec acte : Robotics Science and Systems ( RSS ) 2018 du 26 juin au 30 juin 2018, Pittsburg (USA), Juin 2018, 9p. , N° 18138

Lien : https://hal.archives-ouvertes.fr/hal-01804774

Diffusable

Plus d'informations

Abstract

This paper deals with manipulation planning. The problem consists in automatically computing paths for a system composed of one or several robots, with one or several grippers and one or several objects that can be grasped and moved by the robots. The problem gives rise to constraints that can be either explicit – an object is in a gripper – or implicit – an object is hold by two different grippers. This paper proposes an algorithm that handles such sets of constraints and solves them in an explicit way as much as possible. When all constraints cannot be made explicit, substitution is operated between variables to make the resulting implicit constraint with as few variables as possible. The manipulation planning problem is modelled as a constraint graph that stores all the constraints of the problem.

143737
18003
14/06/2018

SLAM and vision-based humanoid navigation

O.STASSE

GEPETTO

Ouvrage (contribution) : Humanoid Robotics: A Reference, Springer, N°ISBN 978-94-007-6047-9, Juin 2018, 22p. , N° 18003

Lien : https://hal.archives-ouvertes.fr/hal-01674512

Diffusable

142073
17448
01/06/2018

Zero step capturability for legged robots in multi contact

A.DEL PRETE, S.TONNEAU, N.MANSARD

GEPETTO

Revue Scientifique : IEEE Transactions on Robotics, Juin 2018, doi 10.1109/TRO.2018.2820687 , N° 17448

Lien : https://hal.archives-ouvertes.fr/hal-01574687

Diffusable

Plus d'informations

Abstract

The ability to anticipate a fall is fundamental for any robot that has to balance. Currently, fast fall-prediction algorithms only exist for simple models, such as the Linear Inverted Pendulum Model (LIPM), whose validity breaks down in multi-contact scenarios (i.e. when contacts are not limited to a flat ground). This paper presents a fast fall-prediction algorithm based on the point-mass model, which remains valid in multi-contact scenarios. The key assumption of our algorithm is that, in order to come to a stop without changing its contacts, a robot only needs to accelerate its center of mass in the direction opposite to its velocity. This assumption allows us to predict the fall by means of a convex optimal control problem, which we solve with a fast custom algorithm (less than 10 ms of computation time). We validated the approach through extensive simulations with the humanoid robot HRP-2 in randomly-sampled scenarios. Comparisons with standard LIPM-based methods demonstrate the superiority of our algorithm in predicting the fall of the robot, when controlled with a state-of-the-art balance controller. This work lays the foundations for the solution of the challenging problem of push recovery in multi-contact scenarios.

143954
16020
01/06/2018

An efficient acyclic contact planner for multiped robots

S.TONNEAU, A.DEL PRETE, J.PETTRE, C.PARK, D.MANOCHA, N.MANSARD

GEPETTO, IRISA, Yonsei University, North Carolina

Revue Scientifique : International Journal of Robotics Research, Vol.34, N°3, pp.586-601, Juin 2018 , N° 16020

Lien : https://hal.archives-ouvertes.fr/hal-01267345

Diffusable

Plus d'informations

Abstract

We present a framework capable of producing contact plans describing complex multiped motions (including humanoid): standing up, climbing stairs using a handrail, crossing rubble and getting out of a car. Our framework answers a need demonstrated at the Darpa Robotics Challenge, where the lack of an automatic acyclic contact planner was recognized a major issue. Our novel key idea is the reachability condition. Informally, it verifies that the root configuration of a robot is " close, but not too close " from obstacles: close to allow contact creation, not too close to avoid collision. With this approximation of the space of admissible root configurations we decompose the hard contact planning problem into simpler sub-problems: first, to plan a guide path for the root without considering the whole-body configuration; then, to generate a discrete sequence of whole-body configurations in static equilibrium along this path. The reachability condition turns the high-dimensional computation of the guide into a collision checking problem, solved in less than a few seconds. Then a deterministic contact selection algorithm tackles the combinatorial issue of generating of a discrete sequence along the guide path. Several innovations make it computationally efficient: a criterion for verifying static equilibrium, and a set of heuristics used to enforce desirable properties on the configuration. Our approach results from the pragmatic choice of favoring efficiency over exhaustiveness, justified empirically: in a few seconds, with satisfying success rates, we generate complex contact plans for various scenarios and robots, namely HRP-2, HyQ, and a dexterous hand.

144063
17347
29/05/2018

Using a memory of motion to efficiently warm-start a nonlinear predictive controller

N.MANSARD, A.DEL PRETE, M.GEISERT, S.TONNEAU, O.STASSE

GEPETTO

Manifestation avec acte : IEEE International Conference on Robotics and Automation ( ICRA ) 2018 du 21 mai au 25 mai 2018, Brisbane (Australie), Mai 2018, 9p. , N° 17347

Lien : https://hal.archives-ouvertes.fr/hal-01591373

Diffusable

Plus d'informations

Abstract

Predictive control is an efficient model-based methodology to control complex dynamical systems. In general, it boils down to the resolution at each control cycle of a large nonlinear optimization problem. A critical issue is then to provide a good guess to initialize the nonlinear solver so as to speed up convergence. This is particularly important when disturbances or changes in the environment prevent the use of the trajectory computed at the previous control cycle as initial guess. In this paper, we introduce an original and very efficient solution to automatically build this initial guess. We propose to rely on off-line computation to build an approximation of the optimal trajectories, that can be used on-line to initialize the predictive controller. To that end, we combined the use of sampling-based planning, policy learning with generic representations (such as neural networks), and direct optimal control. We first propose an algorithm to simultaneously build a kinodynamic probabilistic roadmap (PRM) and approximate value function and control policy. This algorithm quickly converges toward an approximation of the optimal state-control trajectories (along with an optimal PRM). Then, we propose two methods to store the optimal trajectories and use them to initialize the predictive controller. We experimentally show that directly storing the state-control trajectories leads the predictive controller to quickly converges (2 to 5 iterations) toward the (global) optimal solution. The results are validated in simulation with an unmanned aerial vehicle (UAV) and other dynamical systems.

143613
Les informations recueillies font l’objet d’un traitement informatique destiné à des statistiques d'utilisation du formulaire de recherche dans la base de données des publications scientifiques. Les destinataires des données sont : le service de documentation du LAAS.Conformément à la loi « informatique et libertés » du 6 janvier 1978 modifiée en 2004, vous bénéficiez d’un droit d’accès et de rectification aux informations qui vous concernent, que vous pouvez exercer en vous adressant à
Pour recevoir une copie des documents, contacter doc@laas.fr en mentionnant le n° de rapport LAAS et votre adresse postale. Signalez tout problème de dysfonctionnement à sysadmin@laas.fr. http://www.laas.fr/pulman/pulman-isens/web/app.php/