Laboratoire d’analyse et d’architecture des systèmes
N.STAUB, M.MOHAMMADI, D.BICEGO, Q.DELAMARE, H.YANG, D.PRATTICHIZZO, P.R.GIORDANO, D.LEE, A.FRANCHI
RIS, University of Siena, IRISA, Seoul, IIT, Genova, INRIA Rennes
Revue Scientifique : IEEE Robotics and Automation Magazine, 10p., Décembre 2018, DOI 10.1109/MRA.2018.2871344 , N° 18417
C.GABELLIERI, M.TOGNON, L.PALLOTTINO, A.FRANCHI
Manifestation avec acte : International Conference on Swarm Intelligence ( ANTS ) 2018 du 29 octobre au 31 octobre 2018, Rome (Italie), Novembre 2018, 13p. , N° 18263
This work investigates collaborative aerial transportation by swarms of agents based only on implicit information, enabled by the physical interaction among the agents and the environment. Such a coordinating mechanism in collaborative transportation is a basic skill in groups of social animals. We consider cable-suspended objects transported by a swarm of flying robots and we formulate several hypothesis on the behavior of the overall system which are validated thorough numerical study. In particular, we show that a nonzero internal force reduces to one the number of asymptotically stable equilibria and that the internal force intensity is directly connected to the convergence rate. As such, the internal force represents the cornerstone of a communication-less cooperative manipulation paradigm in swarms of flying robots. We also show how a swarm can achieve a stable transportation despite the imprecise knowledge of the system parameters.
M.TOGNON, H.TELLO CHAVEZ, E.GASPARIN, Q.SABLE, D.BICEGO, A.MALLET, M.LANY, G.SANTI, B.REVAZ, J.CORTES, A.FRANCHI
RIS, Sensima Inspection, IDEA
Rapport LAAS N°18353, Novembre 2018, 9p.
We present the design, control and motion planning of an aerial manipulator for a non-trivial physical interaction task, namely pushing while sliding on curved surfaces. The proposed robotic system is motivated by the increasing interest on autonomous Non-Destructive Tests used for the integrity assessment of industrial plants. The proposed aerial manipulator consists of a multidirectional-thrust aerial vehicle to enhance physical interaction capabilities, endowed with a 2-DoFs lightweight arm to enlarge its workspace. This combination constitutes a truly redundant manipulator that goes beyond standard aerial manipulators with collinear multirotors. The robot controller is based on a PID method with 'displaced' positional part inspired by controllers for manipulators with elastic joints and grounded on several experimental trial-and-error tests. In this work we experimentally show that the proposed aerial manipulator system, equipped with an Eddy Current probe, is able to scan a metallic pipe sliding the sensor over its surface and preserving the contact. From the acquired data, a weld on the pipe is successfully detected and mapped.
M.JUSOT, D.STRATMANN, M.VAISSET, J.CHOMILIER, J.CORTES
RIS, IMPMC, IDEA
Revue Scientifique : Journal of Chemical Information and Modeling, 42p., Octobre 2018, DOI: 10.1021/acs.jcim.8b00375 , N° 18324
Small cyclic peptides represent a promising class of therapeutic molecules with unique chemical properties. However, the poor knowledge of their structural characteristics makes their computational design and structure prediction a real challenge. In order to better describe their conformational space, we developed a method, named EGSCyP, for the exhaustive exploration of the energy landscape of small head-to-tail cyclic peptides. The method can be summarized by (i) a global exploration of the conformational space based on a mechanistic representation of the peptide and the use of robotics-based algorithms to deal with the closure constraint, (ii) an all-atom refinement of the obtained conformations. EGSCyP can handle D-form residues and N-methylations. Two strategies for the side-chains placement were implemented and compared. To validate our approach, we applied it to a set of three variants of cyclic RGDFV pentapeptides, including the drug candidate Cilengitide. A comparative 1 analysis was made with respect to replica exchange molecular dynamics simulations in implicit solvent. It results that the EGSCyP method provides a very complete characterization of the conformational space of small cyclic pentapeptides.
C.MASONE, M.MOHAMMADI, P.R.GIORDANO, A.FRANCHI
Max Planck, IIT, Genova, INRIA Rennes, RIS
Revue Scientifique : International Journal of Robotics Research, 27p., Octobre 2018, doi 10.1177/0278364918802006 , N° 18304
This paper presents a novel bilateral shared framework for online trajectory generation for mobile robots. The robot navigates along a dynamic path, represented as a B-spline, whose parameters are jointly controlled by a human supervisor and by an autonomous algorithm. The human steers the reference (ideal) path by acting on the path parameters which are also affected, at the same time, by the autonomous algorithm in order to ensure: i) collision avoidance, ii) path regularity and iii) proximity to some points of interest. These goals are achieved by combining a gradient descent-like control action with an automatic algorithm that re-initializes the traveled path (replanning) in cluttered environments in order to mitigate the effects of local minima. The control actions of both the human and the autonomous algorithm are fused via a filter that preserves a set of local geometrical properties of the path in order to ease the tracking task of the mobile robot. The bilateral component of the interaction is implemented via a force feedback that accounts for both human and autonomous control actions along the whole path, thus providing information about the mismatch between the reference and traveled path in an integral sense. The proposed framework is validated by means of realistic simulations and actual experiments deploying a quadrotor UAV supervised by a human operator acting via a force-feedback haptic interface. Finally, a user study is presented in order to validate the effectiveness of the proposed framework and the usefulness of the provided force cues.
A.OLLERO, G.HEREDIA, A.FRANCHI, G.ANTONELLI, K.KONDAC, A.S.CORTES, A.VIGURIA, J.R.MARTINEZ-DE-DIOS, F.PIERRI, J.CORTES, A.SANTAMARIA-NAVARRO, M.A.TRUJILLO SOTO, R.BALACHANDRAN, J.ANDRADE-CETTO, A.RODRIGUEZ CASTANO
Seville, RIS, UNICAS, DLR, UPC, CATEC, University of Basilicata, IRI, UPC/CSIC
Revue Scientifique : IEEE Robotics and Automation Magazine, 9p., Octobre 2018, DOI: 10.1109/MRA.2018.2852789 , N° 18297
This paper summarizes new aerial robotic manipulation technologies and methods, required for outdoor industrial inspection and maintenance, developed in the AEROARMS project. It presents aerial robotic manipulators with dual arms and multi-directional thrusters. It deals with the control systems, including the control of the interaction forces and the compliance, the teleoperation, which uses passivity to tackle the trade-off between stability and performance, perception methods for localization, mapping and inspection, and planning methods, including a new control-aware approach for aerial manipulation. Finally, it describes a novel industrial platform with multi-directional thrusters and a new arm design to increase the robustness in industrial contact inspections. The lessons learned in the application to outdoor aerial manipulation for inspection and maintenance are pointed out.
R.BAILON-RUIZ, A.BIT-MONNOT, S.LACROIX
Manifestation avec acte : IEEE/RSJ International Conference on Intelligent Robots and Systems ( IROS ) 2018 du 01 octobre au 05 octobre 2018, Madrid (Espagne), Octobre 2018, 6p. , N° 18261
We present an approach to plan trajectories for a fleet of fixed-wing UAVs to observe a wildfire evolving over time. Realistic models of the terrain, of the fire propagation process, and of the UAVs are exploited, together with a model of the wind. The approach tailors a generic Variable Neighborhood Search method to these models and associated constraints. Simulation results show ability to plan observation trajectories for a small fleet of UAVs, and to update the plans when new information on the fire are incorporated in the fire model.
I.ARDI, H.CARFANTAN, S.LACROIX, A.MONMAYRANT
PHOTO, IRAP, RIS
Manifestation avec acte : European Signal Processing Conference ( EUSIPCO ) 2018 du 03 septembre au 07 septembre 2018, Rome (Italie), Septembre 2018, 5p. , N° 18238
We consider the problem of hyperspectral cube reconstruction with a new controllable 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. We focus here on a quadratic penalty reconstruction approach, which provides a fast resolution thanks to the high sparsity of the involved matrices. While such a regu-larization is known to smooth the restored images, we propose to exploit the system capability to acquire the panchromatic image of the scene, to introduce prior information on the sharp edges of the image, leading to a fast and edge-preserved reconstruction of the image.
A.ESTANA, K.MOLLOY, M.VAISSET, N.SIBILLE, T.SIMEON, P.BERNADO, J.CORTES
CBS, RIS, IDEA
Revue Scientifique : Parallel Computing, Vol.77, pp.84-100, Septembre 2018, DOI 10.1016/j.parco.2018.06.005 , N° 18176
The study of the conformational energy landscape of a molecule is essential for the understanding of its physicochemical properties. This requires the exploration of a continuous, high-dimensional space to identify the most probable conformations and the transition paths between them. The problem is computationally difficult, in particular for highly-flexible biomolecules such as Intrinsically Disordered Proteins (IDPs). In recent years, a robotics-inspired algorithm called Transition-based Rapidly-exploring Random Tree (TRRT) has been proposed to solve this problem, and has been shown to provide good results with small and middle-sized biomolecules. Aiming to treat larger systems, we propose a hybrid strategy for the efficient parallelization of a multi-tree variant of TRRT, called Multi-TRRT, enabling an efficient execution in (possibly large) computer clusters. The parallel algorithm uses OpenMP multi-threading for computation inside each multi-core processor and MPI to perform the communication between processors. Results show a near-linear speedup for a wide range of cluster configurations. Although the paper mainly deals with the application of the proposed parallel algorithm to the investigation of biomolecules, the explanations concerning the methods are general, aiming to inspire future work on the parallelization of related algorithms.
R.CHATILA, E.RENAUDO, M.ANDRIES, R.O.CHAVEZ-GARCIA, P.LUCE-VEYRAC, R.GOTTSTEIN, R.ALAMI, A.CLODIC, S.DEVIN, B.GIRARD, M.KHAMASSI
ISIR, Jussieu, RIS, RAP
Revue Scientifique : Frontiers in Robotics and AI, art.88, Vol.5, 20p., Août 2018 , N° 18248
Despite major progress in Robotics and AI, robots are still basically " zombies " repeatedly achieving actions and tasks without understanding what they are doing. Deep-Learning AI programs classify tremendous amounts of data without grasping the meaning of their inputs or outputs. We still lack a genuine theory of the underlying principles and methods that would enable robots to understand their environment, to be cognizant of what they do, to take appropriate and timely initiatives, to learn from their own experience and to show that they know that they have learned and how. The rationale of this paper is that the understanding of its environment by an agent (the agent itself and its effects on the environment included) requires its self-awareness, which actually is itself emerging as a result of this understanding and the distinction that the agent is capable to make between its own mind-body and its environment. The paper develops along five issues: agent perception and interaction with the environment; learning actions; agent interaction with other agents—specifically humans; decision-making; and the cognitive architecture integrating these capacities.