Retour au site du LAAS-CNRS

Laboratoire d’analyse et d’architecture des systèmes

Publications de l'équipe RIS

Choisir la langue : FR | EN

486documents trouvés

17370
16/10/2017

Fundamental actuation properties of multi-rotors: force-moment decoupling and fail-safe robustness

G.MICHIELETTO, M.RYLL, A.FRANCHI

RIS

Rapport LAAS N°17370, Octobre 2017, 14p.

Lien : https://hal.laas.fr/hal-01612602

Diffusable

Plus d'informations

Abstract

In this paper we shed light on the fundamental actuation capabilities of multi-rotors, such as force-moment decoupling and ability to robustly fly still in place after the loss of propellers. These two actuation properties are formalized through the definition of some necessary algebraic conditions on the control force and control moment input matrices of generically tilted multi-rotors. Standard quadrotors are not able to robustly fly still at a constant spot after the loss of a propeller. The increased number of actuators of a hexarotor does not always help to overcome this limitation. To deeply understand this counterintuitive result, we apply the developed theory on the analysis of fail-safe robustness of hexarotor platforms, and clarify the role of the tilt angles and locations of the propellers in the vehicle. We show that standard star-shaped hexarotors are unable of robust static hovering after a propeller failure, while both the tilted star-shaped hexarotor and the Y-shaped hexarotor possess this important property. The analysis is validated with both simulation and experimental results testing the control of six-rotor vehicles subject to rotor loss.

141240
17339
13/09/2017

A model-checking approach to analyse temporal failure propagation with AltaRica

A.ALBORE, S.DAL ZILIO, G.INFANTES, C.SEGUIN, P.VIRELIZIER

VERTICS, RIS, ONERA, IRT

Manifestation avec acte : International Symposium on Model-Based Safety and Assessment ( IMBSA ) 2017 du 11 septembre au 13 septembre 2017, Trento (Italie), Septembre 2017, 15p. , N° 17339

Lien : https://hal.archives-ouvertes.fr/hal-01590416

Diffusable

Plus d'informations

Abstract

The design of complex safety critical systems raises new technical challenges for the industry. As systems become more complex—and include more and more interacting functions—it becomes harder to evaluate the safety implications of local failures and their possible propagation through a whole system. That is all the more true when we add time to the problem, that is when we consider the impact of computation times and delays on the propagation of failures. We describe an approach that extends models developed for Safety Analysis with timing information and provide tools to reason on the correctness of temporal safety conditions. Our approach is based on an extension of the AltaRica language where we can associate timing constraints with events and relies on a translation into a realtime model-checking toolset. We illustrate our method with an example that is representative of safety architectures found in critical systems.

141115
17257
06/09/2017

Reactive Dubins traveling salesman problem for replanning of information gathering by UAVs

R.PENICKA, M.SASKA, C.REYMANN, S.LACROIX

CTU, RIS

Manifestation avec acte : European Conference on Mobile Robots ( ECMR ) 2017 du 06 septembre au 08 septembre 2017, Paris (France), Septembre 2017, 6p. , N° 17257

Lien : https://hal.archives-ouvertes.fr/hal-01562527

Diffusable

Plus d'informations

Abstract

We introduce a novel online replanning method for robotic information gathering by Unmanned Aerial Vehicles (UAVs) called Reactive Dubins Traveling Salesman Problem (RDTSP). The considered task is the following: a set of target locations are to be visited by the robot. From an initial information gathering plan, obtained as an offline solution of either the Dubins Traveling Salesman Problem (DTSP) or the Coverage Path Planning (CPP), the proposed RDTSP ensures robust information gathering in each given target location by replanning over possible missed target locations. Furthermore, a simple decision making is a part of the proposed RDTSP to determine which target locations are marked as missed and also to control the appropriate time instant at which the repair plan is inserted into the initial path. The proposed method for replanning is based on the Variable Neighborhood Search metaheuristic which ensures visiting of all possibly missed target locations by minimizing the length of the repair plan and by utilizing the preplanned offline solution of the particular information gathering task. The novel method is evaluated in a realistic outdoor robotic information gathering experiment with UAV for both the Dubins Traveling Salesman Problem and the Coverage Path Planning scenarios.

140732
17270
06/09/2017

Viewing robot navigation in human environment as a cooperative activity

H.KHAMBHAITA, R.ALAMI

RIS

Rapport LAAS N°17270, Septembre 2017, 18p.

Lien : https://hal.laas.fr/hal-01572555

Diffusable

Plus d'informations

Abstract

We claim that navigation in human environments can be viewed as cooperative activity especially in constrained situations. Humans concurrently aid and comply with each other while moving in a shared space. Cooperation helps pedestrians to efficiently reach their own goals and respect conventions such as the personal space of others. To meet human comparable efficiency, a robot needs to predict the human trajectories and plan its own trajectory correspondingly in the same shared space. In this work, we present a navigation planner that is able to plan such cooperative trajectories, simultaneously enforcing the robot's kinematic constraints and avoiding other non-human dynamic obstacles. Using robust social constraints of projected time to a possible future collision, compatibility of human-robot motion direction, and proxemics, our planner is able to replicate human-like navigation behavior not only in open spaces but also in confined areas. Besides adapting the robot trajectory, the planner is also able to proactively propose co-navigation solutions by jointly computing human and robot trajectories within the same optimization framework. We demonstrate richness and performance of the cooperative planner with simulated and real world experiments on multiple interactive navigation scenarios.

140650
17225
05/09/2017

Reconstruction d'images hyperspectrales à faible coût pour un imageur pilotable à double dispersion

I.ARDI, H.CARFANTAN, S.LACROIX, A.MONMAYRANT

PHOTO, IRAP, RIS

Manifestation avec acte : Colloque GRETSI sur le traitement du signal et des images ( GRETSI ) 2017 du 05 septembre au 08 septembre 2017, Juan les pins (France), Septembre 2017, 4p. , N° 17225

Lien : https://hal.archives-ouvertes.fr/hal-01562530

Diffusable

Plus d'informations

Résumé

Nous nous intéressons à la reconstruction d'images hyperspectrales (HS) à partir d'un nouveau dispositif d'imagerie pilotable. La reconstruction de l'image à partir d'un faible nombre d'acquisitions pour des configurations différentes de l'imageur permet d'éviter l'acquisition de toute l'image HS par balayage. Notre objectif à terme est de rendre ce dispositif adaptatif en fonction de l'objet observé, ce qui nécessite de disposer de méthodes de reconstruction à faible coût calculatoire. Nous nous focalisons ici sur la reconstruction à l'aide de méthodes de pénalisation quadratique, permettant une résolution directe à faible coût, grâce au caractère très creux des matrices. Abstract – We consisder the problem of hyperspectral image reconstruction with a new controlable imaging system. The reconstruction with a small number of images acquired with different configurations of the imager avoids a complete scanning of the hyperspectral cube. Our objective is to exploit this imager along an adaptive scheme, which requires the ability to reconstruct images in near real-time. We focus here on a quadratic penalty reconstruction approach, which provides a fast direct resolution thanks to the high sparsity of the involved matrices.

140495
17253
01/09/2017

Assessing the social criteria for human-robot collaborative navigation: A comparison of human-aware navigation planners

H.KHAMBHAITA, R.ALAMI

RIS

Manifestation avec acte : IEEE International Symposium on Robot and Human Interactive Communication ( Ro-MAN ) 2017 du 28 août au 01 septembre 2017, Lisbonne (Portugal), Septembre 2017, 6p. , N° 17253

Lien : https://hal.laas.fr/hal-01568841

Diffusable

Plus d'informations

Abstract

This paper focuses on requirements for effective human robot collaboration in interactive navigation scenarios. We designed several use-cases where humans and robot had to move in the same environment that resemble canonical path-crossing situations. These use-cases include open as well as constrained spaces. Three different state-of-the-art human-aware navigation planners were used for planning the robot paths during all selected use-cases. We compare results of simulation experiments with these human-aware planners in terms of quality of generated trajectories together with discussion on capabilities and limitations of the planners. The results show that the human-robot collaborative planner performs better in everyday path-crossing configurations. This suggests that the criteria used by the human-robot collaborative planner (safety, time-to-collision, directional-costs) are possible good measures for designing acceptable human-aware navigation planners. Consequently, we analyze the effects of these social criteria and draw perspectives on future evolution of human-aware navigation planning methods.

140601
17226
31/08/2017

Human-collaborative schemes in the motion control of single and multiple mobile robots mobile robot

A.FRANCHI

RIS

Ouvrage (contribution) : Trends in Control and Decision-Making for Human–Robot Collaboration Systems, Springer, N°ISBN 978-3-319-40532-2, Août 2017, pp.301-324 , N° 17226

Lien : https://hal.laas.fr/hal-01562555

Diffusable

Plus d'informations

Abstract

In this chapter we show and compare several representative examples of human-collaborative schemes in the control of mobile robots, with a particular emphasis on the aerial robot case. We first provide a simplified yet descriptive model of the robot and its interactions. We then use this model to define a taxonomy that highlights the main aspects of these collaboration schemes, such as: the physical domain of the robots, the degree of autonomy, the force interaction with the operator (e.g., the unilateral versus the bilateral haptic shared control), the near-operation versus the teleoperation, the contact-free versus the physically interactive situation, the use of onboard sensors, and the presence of a time-horizon in the operator reference. We then specialize the proposed taxonomy to the multi-robot case in which we further distinguish the methods depending on their level of centralization, the presence of leader-follower schemes, of formation control schemes, the ability to preserve graph theoretical properties, and to perform cooperative physical interaction. The common denominator of all the examples presented in this chapter is the presence of a human operator in the control loop. The main goal of the chapter is to introduce the reader and provide a first-level analysis on the several ways to effectively include human operators in the control of both single and multiple aerial robots and, by extension, of more generic mobile robots.

140497
17220
30/08/2017

Cooperative aerial transportation without communication: the role of internal force for pose regulation

M.TOGNON, C.GABELLIERI, L.PALLOTTINO, A.FRANCHI

RIS, Pise

Rapport LAAS N°17220, Août 2017, 7p.

Lien : https://hal.laas.fr/hal-01551105

Diffusable

Plus d'informations

Abstract

This paper considers the study of cooperative transportation of a cable-suspended load with two aerial robots and without explicit communication. The role of the internal force for the asymptotic stability of the beam-position/beam-attitude equilibria is analyzed in depth and explained thoroughly. Using a nonlinear Lyapunov-based approach, we prove that that if a non-zero internal force is chosen then asymptotic stabilization of any desired beam-position/beam-attitude configuration can be achieved by using a decentralized and communication-less master-slave admittance controller. If, conversely , a zero internal force is chosen, as done in the majority of the state-of-the-art algorithms, the attitude of the beam is not controllable without communication. Non-zero internal force can be interpreted then as a fundamental factor that enables the use of cables as implicit communication means between the two aerial vehicles in replacement of the explicit ones. The theoretical findings are validated through numerical simulations with added noise and realistic uncertainty.

140467
17200
29/07/2017

Can robot navigation bugs be found in simulation? An exploratory study

T.SOTIROPOULOS, H.WAESELYNCK, J.GUIOCHET, F.INGRAND

TSF, RIS

Manifestation avec acte : IEEE International Conference on Software Quality, Reliability and Security ( QRS ) 2017 du 25 juillet au 29 juillet 2017, Prague (République Tchèque), Juillet 2017, 10p. , N° 17200

Lien : https://hal.archives-ouvertes.fr/hal-01534235

Diffusable

Plus d'informations

Abstract

The ability to navigate in diverse and previously unknown environments is a critical service of autonomous robots. The validation of the navigation software typically involves test campaigns in the field, which are costly and potentially risky for the robot itself or its environment. An alternative approach is to perform simulation-based testing, by immersing the software in virtual worlds. A question is then whether the bugs revealed in real worlds can also be found in simulation. The paper reports on an exploratory study of bugs in an academic software for outdoor robots navigation. The detailed analysis of the triggers and effects of these bugs shows that most of them can be revealed in low-fidelity simulation. It also provides insights into interesting navigation scenarios to test as well as into how to address the test oracle problem.

140374
17106
14/07/2017

Visual Marker based Multi-Sensor Fusion State Estimation

J.L.SANCHEZ LOPEZ, V.ARELLANO, M.TOGNON, P.CAMPOY

UPM, RIS

Manifestation avec acte : IFAC World Congress 2017 du 09 juillet au 14 juillet 2017, Toulouse (France), Juillet 2017, 6p. , N° 17106

Lien : https://hal.laas.fr/hal-01501980

Diffusable

Plus d'informations

Abstract

This paper presents the description and experimental results of a versatile Visual Marker based Multi-Sensor Fusion State Estimation that allows to combine a variable optional number of sensors and positioning algorithms in a loosely-coupling fashion, incorporating visual markers to increase its performances. This technique allows an aerial robot to navigate in different environments and carrying out different missions with the same state estimation architecture, exploiting the best from every sensor. The state estimation algorithm has been successfully tested controlling a quadrotor equipped with an extra IMU and a RGB camera used only to detect visual markers. The entire framework runs on an onboard computer, including the controllers and the proposed state estimator. The whole software is made publicly available to the scientific community through an open source implementation.

140673
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/