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International audience; This paper addresses the parameter estimation issue on mobile robots. A comparison between the state-of-art Least-Squares Technique and the potentially useful Instrumental Variable Method is carried out. With that objective, the whole process of kinematic and dynamic modeling, exciting trajectory design, simulation, parameter identification and cross-validation is done. The results are shown in simulation of a Differential Drive Mobile Robot to show that against possible noises and perturbations on mobile robotics, due to effects as slipping and not perfect rolling, Instrumental Variable gives a better performances. A model considering an unbalanced mass distribution of the mobile robot is derived and validated.

In recent years, collaborative robots have become one of the main drivers of Industry 4.0. Compared to industrial robots, automated guided vehicles (AGVs) are more productive, flexible, versatile, and safer. They are used in the smart factory to transport goods. Today, many producers and developers of industrial robots have entered the AGV sector. However, they face several challenges in designing AGV systems, such as the complexity and discontinuity of the design process, as well as the difficulty of defining a decentralized system decision. In this paper, we propose a new integrated design methodology based on swarm robotics to address the challenges of functional, physical, and software integration. This methodology includes two phases: a top-down phase from requirements specification to functional and structural modeling using the systems modeling language (SysML), with a bottom-up phase for model integration and implementation in the robot operating system (ROS). A case study of an automated guided vehicle (AGV) system was chosen to validate our design methodology and illustrate its contributions to the efficient design of AGVs. The novelty of this proposed methodology is the combination of SysML and ROS to address traceability management between the different design levels of AGV systems, in order to achieve functional, physical and software integration.

To date, ethical critiques of the use of assistive healthcare robotics have not closely examined the purported care relationship between such robots and their users. Drawing upon the work of care ethics scholars, I argue that authentic care relies upon capacities inherently reciprocal and responsive in nature, which ultimately precludes socially assistive robots from being useful caring tools., Jusqu’à présent, les critiques éthiques de l’utilisation de la robotique d’assistance médicale n’ont pas examiné de près la prétendue relation de soins entre ces robots et leurs utilisateurs. En m’appuyant sur les travaux des spécialistes de l’éthique des soins, je soutiens que les soins authentiques reposent sur des capacités intrinsèquement réciproques et réactives par nature, ce qui empêche en définitive les robots d’assistance sociale d’être des outils de soins utiles.

Human-Robot Interaction (HRI) is a largely addressed subject today. In order to ensure co-existence and space sharing between human and robot, collision avoidance is one of the main strategies for interaction between them without contact. It is thus usual to use a 3D depth camera sensor (Microsoft Kinect V2) which may involve issues related to occluded robot in the camera view. While several works overcame this issue by applying infinite depth principle or increasing the number of cameras, in the current work we developed and applied an original new approach that combines data of one 3D depth sensor (Kinect) and proprioceptive robot sensors. This method uses the principle of limited safety contour around the obstacle to dynamically estimate the robot-obstacle distance, and then generate the repulsive force that controls the robot. For validation, our approach is applied in real time to avoid collisions between dynamical obstacles (humans or objects) and the end-effector of a real 7-dof Kuka LBR iiwa collaborative robot. Our method is experimentally compared with existing methods based on infinite depth principle when the robot is hidden by the obstacle with respect to the camera view. Results showed smoother behavior and more stability of the robot using our method. Extensive experiments of our method, using several strategies based on distancing and its combination with dodging were done. Results have shown a reactive and efficient collision avoidance, by ensuring a minimum obstacle-robot distance (of $\approx \text{240 mm}$ ), even when the robot is in an occluded zone in the Kinect camera view.

International audience; Human-Robot Interaction (HRI) is a largely ad-dressed subject today. Collision avoidance is one of main strategies that allow space sharing and interaction without contact between human and robot. It is thus usual to use a 3D depth camera sensor which may involves issues related to occluded robot in camera view. While several works overcame this issue by applying infinite depth principle or increasing the number of cameras, we developed in the current work a new and an original approach based on the combination of a 3D depth sensor (Microsoft® Kinect V2) and the proprioceptive robot position sensors. This method uses a principle of limited safety contour around the obstacle to dynamically estimate the robot-obstacle distance, and then generate the repulsive force that controls the robot. For validation, our approach is applied in real time to avoid collision between dynamical obstacles (humans or objects) and the end-effector of a real 7-dof Kuka LBR iiwa collaborative robot.Several strategies based on distancing and its combination with dodging were tested. Results have shown a reactive and efficient collision avoidance, by ensuring a minimum obstacle-robot distance (of ≈ 240mm), even when the robot is in an occluded zone in the Kinect camera view.

In this era of industrialization, a lot has been accomplished by robots particularly in developed countries to improve the nations’ economies. The six major areas of robotics which are expected to make major economic impact and contribute to national development include : drones, artificial assistants, driverless cars, medical procedures, operations, prosthetics, and exoskeleton. Most robots increase productivity, improve workers’ safety and make work more comfortable. Furthermore, robots help humans with odd jobs that are dangerous. It is expected therefore that deployment of robots can lead to economic growth and national development in Nigeria. This is a position paper that will enlighten Nigeria as a nation on the need for robots which will serve as a remedy for resuscitating her dwindling economy. The study was anchored on two theories namely : Technological Determinism and Social Construction of Technology Theories. The related literature was reviewed and the paper discussed and analysed succinctly. Appropriate communication strategies to create awareness among Nigerians were postulated. It is revealed that the benefits of robots outweigh the challenges thus the need for the deployment of robots in Nigeria. Four recommendations were made, one of which is that the government should establish Federal Agency for robots and robotics in Nigeria to create awareness, monitor and oversee the smooth running of deployment of robots. En cette ère d'industrialisation, les robots ont permis des avancées dans l'amélioration des économies nationales, en particulier dans les pays développés, pour améliorer l'économie des nations. Les six principaux domaines de la robotique qui devraient avoir un impact économique majeur et contribuer au développement national sont les suivants : les drones, les assistants artificiels, les voitures sans conducteur, les procédures médicales, les opérations, les prothèses et les exosquelettes. La plupart des robots augmentent la productivité, améliorent la sécurité des travailleurs et rendent le travail plus confortable. En outre, les robots aident les humains à effectuer des petits travaux dangereux. On s'attend donc à ce que le déploiement de robots puisse conduire à la croissance économique et au développement national au Nigeria. Cette prise de position éclairera le Nigéria en tant que nation sur le besoin de robots comme remède à une économie en déclin. L'étude s'appuie sur deux théories, à savoir le déterminisme technologique et la construction sociale des théories technologiques. La littérature correspondante a été passée en revue et le document a été discuté et analysé de manière succincte. Des stratégies de communication appropriées pour sensibiliser les Nigérians ont été proposées. Il s'avère que les avantages des robots l'emportent sur les difficultés, d'où la nécessité de déployer des robots au Nigeria. Quatre recommandations ont été formulées, dont l'une est que le gouvernement devrait créer une agence fédérale pour les robots et la robotique au Nigeria afin de sensibiliser, de contrôler et de superviser le bon déroulement du déploiement des robots. In dieser Ära der Industrialisierung haben Roboter vor allem in den entwickelten Ländern viel erreicht, um die Wirtschaft der Nationen zu verbessern. Zu den sechs Hauptbereichen der Robotik, die große wirtschaftliche Auswirkungen haben und zur nationalen Entwicklung beitragen dürften, gehören: Drohnen, künstliche Assistenten, fahrerlose Autos, medizinische Verfahren, Operationen, Prothesen und Exoskelett. Die meisten Roboter erhöhen die Produktivität, verbessern die Sicherheit der Arbeitnehmer und machen die Arbeit komfortabler. Darüber hinaus helfen Roboter Menschen bei Gelegenheitsarbeiten, die gefährlich sind. Es wird daher erwartet, dass der Einsatz von Robotern zu Wirtschaftswachstum und nationaler Entwicklung in Nigeria führen kann. Dies ist ein Positionspapier, das Nigeria als Nation über den Bedarf an Robotern aufklären wird, die als Heilmittel zur Wiederbelebung seiner schrumpfenden Wirtschaft dienen sollen. Die Studie basiert auf zwei Theorien, nämlich: Technologischer Determinismus und soziale Konstruktion von Technologietheorien. Die diesbezügliche Literatur wurde gesichtet und das Papier kurz und bündig diskutiert und analysiert. Geeignete Kommunikationsstrategien zur Bewusstseinsbildung unter den Nigerianern wurden postuliert. Es zeigt sich, dass die Vorteile von Robotern die Herausforderungen überwiegen und somit die Notwendigkeit des Einsatzes von Robotern in Nigeria. Es wurden vier Empfehlungen ausgesprochen, von denen eine lautet, dass die Regierung eine Bundesagentur für Roboter und Robotik in Nigeria einrichten sollte, um das Bewusstsein für den Einsatz von Robotern zu schärfen und den reibungslosen Ablauf zu überwachen und zu kontrollieren.

Nowadays, the concept of programmable matter paves the way for promising applications such as reshaping an object to test different configurations, modeling or rapid prototyping. Based on elementary modules, such matter can be arranged and disassembled easily according to the needs of the designers. Several solutions have been proposed to implement this concept. Most of them are based on modular self-reconfigurable robotics (SMR) that can work together and move relatively to one another in order to change their configuration. Achieving such behavior requires to solve some technological challenges in particular module&rsquo, s geometry and actuation. In this paper, we build and develop a proof of concept for a catom based on electrostatic actuation. The modeling and analysis of the actuator functioning as catom is given after a comparison of various possible actuation. Simulations as well as experiments validations are afterwards carried out to confirm and demonstrate the efficiency of electrostatic actuation to achieve latching capabilities of the proposed catom.

International audience; The human-robot collaboration is a promising and challeng- ing field of robotics research. One of the main collaboration tasks is the object co-manipulation where the human and robot are in a continuous physical interaction and forces exerted must be handled. This involves some issues known in robotics as physical Human-Robot Interaction (pHRI), where human safety and interaction comfort are required. Moreover, a definition of interaction quality metrics would be relevant. In the current work, the assessment of Human-Robot object co-manipulation task was explored through the proposed metrics of interaction quality, based on human forces throughout the movement. This analysis is based on co-manipulation of objects with different dynamical properties (weight and inertia), with and without including these properties knowledge in the robot control law. Here, the human is a leader of task and the robot the follower without any information of the human trajectory and movement profile. For the robot control law, a well-known impedance control was applied on a 7-dof Kuka LBR iiwa 14 R820 robot. Results show that the consideration of object dynamical properties in the robot control law is crucial for a good and more comfortable interaction. Besides, human efforts are more significant with a higher no-considered weight, whereas it remains stable when these weights were considered.

Resume Introduction Malgre une diminution du nombre de prostatectomies totales en France, la proportion de prostatectomies assistees par robot augmente. L’objectif de ce travail est de faire une mise au point comparant les resultats de la prostatectomie robot-assistee avec ceux des voies d’abord ouverte et cœlioscopique. Materiel et methodes Une revue systematique de la litterature sur PubMed a ete effectuee. Les etudes prospectives ainsi que les meta-analyses comparant prostatectomie totale robot-assistee (PTAR), laparoscopique (PTL) et par chirurgie ouverte (PTCO) ont ete retenues. Resultats La fonction erectile etait significativement meilleure apres PTAR qu’apres PTL. Comparativement a la PTCO, la sexualite etait d’apres des meta-analyses, significativement meilleure a 12 mois et le risque absolu de dysfonction erectile significativement diminue. La continence apres PTAR etait significativement meilleure, et des 3 mois, qu’apres PTL. Comparativement a la PTCO, le taux de patients continents etait discordant, tantot significativement meilleurs pour la PTAR, tantot sans difference. Le taux de marges positives etait similaire entre les techniques de PTAR, PTL et PTCO. Le suivi a long terme montrait des resultats equivalents sous reserve d’un recul insuffisant. En termes de complications peri-operatoires, aucune difference significative n’a ete observee entre la PTAR comparativement a la de PTL ou PTCO. Conclusion La PTAR offre les memes garanties oncologiques que les voies ouvertes et laparoscopique. La continence et la sexualite sont meilleures qu’en laparoscopie et par voie ouverte. Il n’existe toutefois pas d’etude randomisee a long terme comparant PTAR et PTCO. Ces donnees sont importantes a connaitre pour justifier d’un codage specifique CCAM.

International audience; This paper addresses the important topic of electro-mechanical systems identification with an application in robotics. The standard inverse dynamic identification model with least squares (IDIM-LS) method of identifying models for robotic systems is based on the use of a continuous-time inverse dynamic model whose parameters are identified from experimental data by linear LS estimation. The paper describes a new alternative but related approach that exploits the state-dependent parameter (SDP) method of nonlinear model estimation and compares its performance with that of IDIM-LS. The SDP method is a two-stage identification procedure able to identify the presence and graphical shape of nonlinearities in dynamic system models with a minimum of a priori assumptions. The performance of the SDP method is evaluated on two electro-mechanical systems: the electro-mechanical positioning system and the second link of the TX40 robot. The experimental results demonstrate how SDP identification helps to avoid over-reliance on prior conceptions about the nature of the nonlinear characteristics and correct any deficiencies in this regard. Finally, a simulation study shows how the resulting SDP model is able to facilitate nonlinear control system design using linear-like design procedures.

International audience; Des ensembles de données spatio-temporelles (DST) sont générés quotidiennement. Généralement, leur visualisation est basée sur des rendus 2D ou des visualisations animées, peu adaptés à l’exploration de telles données. Dans cet article, nous présentons une alternative aux approches existantes en termes de visualisations. Notre approche propose d'explorer la combinaison d'interfaces tangibles, de robots et d'un écran tactile pour faciliter l’accès, l’interprétation et la manipulation de ce type de données. Si l'apport des interfaces tangibles a déjà été exploré pour représenter des informations simples, notre approche vise à dépasser ces associations directes pour permettre d'explorer des ensembles de données multidimensionnelles au-delà de la 3D.; Spatio-temporal datasets (STD) are generated daily. Generally, their visualization includes 2D renderings or animated visualizations that do not fit to the exploration of such complex data. In this paper, we present an alternative approach to current STD visualizations. Our approach uses tangible and visual tools such as mini-robots and a tactile interaction screen to facilitate access, interpretation and manipulation of this kind of data. While tangible elements have been introduced to represent information, our system provides a new approach to explore multidimensional datasets that conventional tools would not allow.

International audience; This paper studies the impact of the accelerated thermal aging on the conducted emission produced by a synchronous buck converter. The most degraded devices mounted on the DC-DC converter are identified and modeled in order to simulate the evolution of conducted emission and anticipate risks of non-compliance to emission requirements.

International audience; This paper deals with two robot identification methods recently introduced. The first one is based on the use of the Inverse Dynamic Identification Model (IDIM) and the Instrumental Variable (IV). The second one is the Direct andInverse Dynamic Identification Models (DIDIM) method, whichis a closed-loop output error method minimizing the quadratic error between the actual and simulated joint torques. Both methods rely on the simulation of the Direct Dynamic Model(DDM). They are compared with a six degrees of freedom industrial robot. The experimental results show that the DIDIM method has the advantage of requiring less data preprocessing. Nevertheless, the IDIM-IV method appears to be more robust to modelling errors in the simulation which are not located in the identified dynamic model.

International audience; Identification of industrial robots is a prolific topic that has been deeply investigated over the last three decades. The standard method is based on the use of the inverse dynamic model and the least-squares estimation (IDIM-LS method) while robots are operating in closed loop by tracking exciting trajectories. Recently, in order to secure the consistency of the parameters estimates, an instrumental variable (IV) approach, called IDIM-IV method, has been designed and experimentally validated. However, the statistical analysis of estimates was not treated. Surprisingly, this topic is rarely addressed in mechatronics whereas it has been deeply investigated in automatic control. This paper aims at bridging the gap between these two communities by presenting a pragmatic statistical analysis of the IDIM-IV estimates. This analysis consists of a two-step procedure: first, the consistency of the IDIM-IV estimates is validated by the Revised Durbin-Wu-Hausman test, and then the statistical analysis of the IDIM-IV residuals is treated. This two-step approach is experimentally validated on the TX40 robot.

International audience; We present an evaluation and a comparison of different Visual Odometry algorithms, selected to be tested on a mobile device equipped with a RGB-D camera. The most promising algorithms from the literature are tested on different mobile devices, some equipped with the Structure Sensor. We evaluate the accuracy of each selected algorithm as well as the the memory and CPU consumption, and we show that even without specific optimization, some of them can provide a reliable measure of the device motion in real time.

This paper deals with the important topic of rigid industrial robots identification. The usual identification method is based on the use of the inverse dynamic model and the least-squares technique. In order to obtain good results, a well-tuned derivative bandpass filtering of joint positions is needed to calculate the joint velocities and accelerations. However, we can doubt whether the bandpass filter is well-tuned or not. Another approach is the instrumental variable (IV) method which is robust to data filtering and which is statistically optimal. In this paper, an IV approach relevant for identification of rigid industrial robots is introduced. The set of instruments is the inverse dynamic model built from simulated data which are calculated from the simulation of the direct dynamic model. The simulation assumes the same reference trajectories and the same control structure for both the actual and the simulated robot and is based on the previous IV estimates. Furthermore, to obtain a rapid convergence, the gains of the simulated controller are updated according to IV estimates. Thus, the proposed approach validates the inverse and direct dynamic models simultaneously and is not sensitive to initial conditions. The experimental results obtained with a 2 degrees of freedom (DOF) planar prototype and with a 6 DOF industrial robot show the effectiveness of our approach: it is possible to identify 60 parameters in 3 iterations and in 11 s.

International audience; The most widely-used technique to generate wholebody motions on a humanoid robot accounting for various tasks and constraints is the inverse kinematics. Based on the taskfunction approach, this class of methods makes possible the coordination of the robot movements to execute several tasks in parallel and account for the sensor feedback, in real-time thanks to the low computation cost. To some extent, it also enables dealing with some of the robot constraints (e.g. joint limits or visibility) and managing the quasi-static balance of the robot. In order to fully use the whole range of possible motions, this paper proposes to extend the task-function approach to handle the full dynamics of the robot multi-body along with any constraint written as equality or inequality of the state and control variables. The definition of multiple objectives is made possible by ordering them inside a strict hierarchy. Several models of contact with the environment can be implemented in the framework. We propose a reduced formulation of the multiple rigid planar contact that keeps a low computation cost. The efficiency of this approach is illustrated by presenting several multi-contact dynamic motions in simulation and on the real HRP-2 robot.

International audience; Robot localization is a mandatory ability for the robot to navigate the world. Solving the SLAM (Simultaneous Localization and Mapping) allows the robot to both localize itself in the environment while building a map of its surrounding. Vision-based SLAM uses one or more camera as the main source of information. The SLAM involves a large computation load on its own and using vision involves even more complexity that does not scale well. This increasing complexity makes it hard to solve in real-time for applications where the SLAM high rate and low latency are inherent constraints (Advanced Drivers Assistance Systems). To help robots solve the SLAM in real-time we propose to build a vision-core that aims at processing the pixel stream coming from the camera in a vision front-end that let a SLAM method work only with high-level features extracted from the image. This paper describes the implementation on FPGA of a core that computes the BRIEF descriptor from a camera output. We also present the implementation of the correlation method for this descriptor for the tracking in an image sequence. This core is then tested in an embedded SLAM application with good speed-up.

Minimally invasive surgery (MIS) can be considered as the greatest surgical innovation over the past thirty years. It revolutionized surgical practice with well-proven advantages over traditional open surgery: reduced surgical trauma and incision-related complications, such as surgical-site infections, postoperative pain and hernia, reduced hospital stay, and improved cosmetic outcome. Nonetheless, proficiency in MIS can be technically challenging as conventional laparoscopy is associated with several limitations as the two-dimensional (2D) monitor reduction in-depth perception, camera instability, limited range of motion and steep learning curves. The surgeon has a low force feedback which allows simple gestures, respect for tissues and more effective treatment of complications. Since 1980s several computer sciences and robotics projects have been set up to overcome the difficulties encountered with conventional laparoscopy, to augment the surgeon's skills, achieve accuracy and high precision during complex surgery and facilitate widespread of MIS. Surgical instruments are guided by haptic interfaces that replicate and filter hand movements. Robotically assisted technology offers advantages that include improved three- dimensional stereoscopic vision, wristed instruments that improve dexterity, and tremor canceling software that improves surgical precision.

International audience; In this paper, we propose the use of compliant elements in the actuation of a wheel-legged robot in order to improve its locomotion properties on unknown and irregular terrains. Detection of the obstacles is achieved by a synergistic use of the structural compliances. The robot's capabilities to surmount steep obstacles is thus improved thanks to the inertia of the chassis and flexibility in postural control. In the proposed robot's kinematics, the four wheels are attached to the main body through vertical series elastic actuators (SEA) and with a passive horizontal compliant mechanism subject to a specific wheel speed control. The overall control relies on postural servoing and a local reactive loop which adapts the vertical forces applied by the SEA on each wheel according to the detected obstacle and the stability margin. The resulting system is evaluated with physical simulations for two case studies : a canonical steep obstacle on one wheel at a time and multiple random rough terrains.

International audience; This paper proposes a concept of navigation and guidance strategy planner for urban operation of a VTOL-type UAV. One of major challenges of UAV autonomous navigation in an urban environment is to deal with the risk of GPS signal occlusion. In order to address this issue, various approaches have been proposed for GPS-independent UAV navigation and guidance such as visual odometry and visual servoing control. In this context, this work supposes that different navigation and guidance modes using different set of sensors are available onboard an UAV. An idea of the proposed planner is to anticipate the navigation and guidance performance degradation (or amelioration) due to unavailability (or availability) of certain mode in the path planning task. The planning problem is formulated as a 5D (3D position + selection of navigation and guidance modes) graph search problem, where the localization and path execution uncertainties are propagated according to a model of corresponding modes for each node transition. Node transition is denied if the path execution uncertainty ellipsoid intersects with any obstacle. A minimizing cost function is defined by a volume of the path execution uncertainty corridor, as it implies minimizing path distance and execution accuracy at the same time. A deterministic graph search algorithm is applied to find a flight path with specified navigation and guidance mode transitions which minimizes the defined cost function. Simulations are performed by using path planning configurations given in an existing UAV obstacle field navigation benchmark, and the results are presented to prove the proposed navigation and guidance strategy planning concept.

Purpose The paper presents the optimization of the power flows inside a microgrid with renewable sources and two kinds of storage. The considered microgrid consists in commercial buildings with maximum daily peak value of 50 kW, photovoltaic arrays with total capacity of 175 kW, a 50 kW/50 kWh high speed flywheel storage and a 50 kW/50 kWh set of Li-ion accumulators. Design/methodology/approach The power flows in the microgrid are optimized the day ahead at one hour discretization in order to minimize the electric bill. Several scheduling strategies are proposed for solving the corresponding optimization problem including standard deterministic methods, stochastic algorithms and hybrid heuristics. Findings All scheduling strategies investigated in the paper are compared with regard to their accuracy and computational time. Originality/value Beyond the comparison of different algorithms devoted to the power flow optimization problem, our approach also addresses the integration of battery ageing in the scheduling strategy.

International audience; This paper presents the evolution of an airliner fan BLDC motor to adapt it to an HVDC electrical network. The guiding principle of the design is to increase reliability. A non-overlapping teeth winding is introduced to separate the motor phases in order to limit winding failures and especially partial discharges. The machine is also optimised using spoke-type magnets flux concentration rotor, in order to reduce total mass. The new machine is compared to the existing one with a finite elements method analysis.

International audience; Current robotics advances offer consequent potential for assistance, not only for individuals, but also for professionals operating on the ground, such as firemen or military. However, such operators must stay focused on their mission; hence they expect a non-invasive, intuitive control system, disrupting them as least as possible. Furthermore, the inherent mobility arising from such missions (walking, running, jumping) must not be an obstacle to gesture recognition. Here, we present a glove-based gesture detection algorithm, whose learning phase is instantaneous among a large span of possible gestures. It has been evaluated on a seven-word dictionary dedicated for the purpose of robot control, with satisfying recognition results.; Les progrès actuels de la robotique offrent des opportunités considérables , pas seulement pour les particuliers mais également les professionnels en mission, tels que des pompiers ou militaires. Cependant, ce type d'opérateurs doit rester focalisé sur sa mission et attend donc un moyen de contrôle qui soit peu intrusif et tr es intuitif. De plus, il est indispensable de livrer un système qui prend en compte la mobilité intrinsèque à ce type d'activité (marche, course, saut). Nous présentons ici un système de reconnaissance gestuelle à base de gant de données , à l'apprentissage instantané sur une large gamme de gestes possibles. Nous l'avons évalué sur sept gestes dédiés au contrôle d'un robot mobile, avec des résultats tout à fait satisfaisants.

International audience; This work deals with the generation of human-like whole-body movements on anthropomorphic systems. We propose a general framework to generate robot movements from the definition of ordered stack of tasks and a global resolution scheme that enables to consider different kinds of constraints. We compare qualitatively the robot movements generated from this software with similar recorded human movements. We start with a direct global comparison of body movements. Then we analyze the magnitude of the reconstructed human torques and compare with the simulated robot torques during the motion.

International audience; Evaluating dependability of complex systems requires the evolution of the system states over time to be analysed. The problem is to develop modelling approaches that take adequately the evolution of the different operating and failed states of the system components into account. The Fault Tree (FT) is a well- known method that efficiently analyse the failure causes of a system and serves for reliability and availability evaluations. As FT is not adapted to dynamic systems with repairable multi-state compo- nents, extensions of FT (eFT) have been developed. However efficient quantitative evaluation processes of eFT are missing. Petri nets have the advantage of allowing such evaluation but their construction is difficult to manage and their simulation performances are unsatisfactory. Therefore, we propose in this paper a new powerful process to analyse quantitatively eFT. This is based on the use of PN method, which relies on the failed states highlighted by the eFT, combined with a new analytical modelling approach for critical events that depend on time duration. The performances of the new process are demonstrated through a theoretical example of eFT and the practical use of the method is shown on a satellite-based railway system.

International audience; Active vision-based robot design involves a variety of techniques and formalisms, from kinematics to control theory, signal processing and computer science. The programming of such systems therefore requires environments with many different functionalities, in a very integrated fashion in order to ensure consistency of the different parts. In significant applications, the correct specification of the global controller is not simple to achieve, as it mixes different levels of behavior, and must respect properties. In this paper we want to advocate the use of a strongly integrated environment able to deal with the design of such systems from the specification of both continuous and discrete parts down to the verification of dynamic behavior. The synchronous language signal is used here as a candidate integrated environment for the design of active vision systems. Our experiments show that signal, while not being an environment devoted to for robotics (but more generally dedicated to control theory and signal processing), presents functionalities and a degree of integration that are relevant to the safe design of active vision-based robotics system.

The work presented in this article shows, through a case study, the different stages of designing a fault tolerant system; a system which can tolerate faults without losing its operational capability. This system includes a gripper mounted on the wrist of a robot manipulator. First the faults were identified, then the residual generation stage was designed. Analyzing this residual allows us to show that artificially injected faults can be detected and an alarm is generated for an emergency stop command. With regards to the gripper, we have only dealt with the faults we were able to solve thanks to the accommodation stage which must control both hardware and software reconfigurations. The considered faults originated in the electronic interfaces and for an efficient supervision we have designed the whole gripper control. The electronic interfaces concerned by fault occurrence are duplicated to ensure robot task continuity.

In this work, we present a model based on social referencing mechanisms for the artwork appreciation development. We show that trying to reach autonomous robot artwork preferences is an interesting framework for developmental robotics. Therefore, we present an application of our model in a natural environment. The museum as an experiment place, helps us to benefit from a large number of visitors with different backgrounds and personal interests, as well as provides the challenge of the learning and recognition of an important number of artefacts (heterogeneous set of objects in terms of size, culture). To overcome some limitations like the autonomy in the learning, we proposed a first model for cumulative learning using a second-order conditioning approach with very encouraging results.

We are interested in human motion characterization and automatic motion simulation. The apparent redundancy of the humanoid w.r.t its explicit tasks lead to the problem of choosing a plausible movement in the framework of redundant kinematics. This work explores the intrinsic relationships between singular value decomposition at kinematic level and optimization principles at task level and joint level. Two task-based schemes devoted to simulation of human motion are then proposed and analyzed. These results are illustrated by motion captures, analyses and task-based simulations. Pattern of singular values serve as a basis for a discussion concerning the similarity of simulated and real motions.

This article discusses some of the associated difficulties in designing system architecture for the autonomous control of a mobile robot, in particular the problem associated with using strategic reasoning for selecting a set of "activities". An activity is designed as a stand alone sub-system capable of performing a particular focused task. Strategic reasoning is coded as a set of production rules and interaction between the activities and the strategic reasoning knowledgebase occurs through blackboard style architecture. The system architecture described in this article is known as a blackboard activity-based system and came about from a study of desired attributes for mobile robot system architecture. A definition of these attributes is given along with a qualitative comparison of several classical system architectures. The blackboard activity-based system is a hybrid system incorporating advantages of the three classical systems. It is designed with two hierarchical layers for strategic and reactive reasoning, a blackboard database for keeping track of the global state of the world, and a set of reactive behaviour-like activities. The feasibility of the approach is demonstrated by an actual implementation on a mobile platform which has the ability of real-time reactive navigation, detection of floor anomalies, and dynamic path planning. An example of strategic reasoning is demonstrated when information posted on the blackboard by the passageway activity is used to guide the floor anomaly activity.

This paper deals with the topic of robots dynamics identification. In this paper, we focus on the instrumental variable (IV) technique. For robots, the set of instruments is the inverse dynamic model built from simulated data which are calculated from the integration of the direct dynamic model, assuming the same reference trajectories and the same control law structure for both actual and simulated robots. The integration of the direct dynamic model is based on previous IV estimates. This defines an iterative algorithm. Furthermore, gains of the simulated controller are updated to get a fast convergence. Experimental results obtained on a six degrees of freedom robot manufactured by Staubli show the effectiveness of our approach: 60 dynamic parameters are estimated in only two iterations.

International audience; Detecting the task a user is performing on her computer desktop is important for providing her with contextualized and personalized support. Some recent approaches propose to perform automatic user task detection by means of classifiers using captured user context data. In this paper we improve on that by using an ontology-based user interaction context model that can be automatically populated by (i) capturing simple user interaction events on the computer desktop and (ii) applying rule-based and information extraction mechanisms. We present evaluation results from a large user study we have carried out in a knowledge-intensive business environment, showing that our ontology-based approach provides new contextual features yielding good task detection performance. We also argue that good results can be achieved by training task classifiers 'online' on user context data gathered in laboratory settings. Finally, we isolate a combination of contextual features that present a significantly better discriminative power than classical ones.

SummaryRadiofrequency treatment is the first-choice treatment for arrhythmias, in particular complex arrhythmias and especially atrial fibrillation, due to the greater benefit/risk ratio compared with antiarrhythmic drugs. However, complex arrhythmias such as atrial fibrillation require long procedures with additional risks such as X-ray exposure or serious complications including tamponade. Given this context, robotic magnetic navigation is a technique well suited to the treatment of complex arrhythmias, on account of its efficacy and reliability, the significant reduction in X-ray exposure for both patient and operator, and the very low risk of perforation. As ongoing developments will likely improve results and procedure times, this technology will become one of the most advanced for treating arrhythmias.

International audience; We address the problem of multi-sensor-based navigation in a cluttered environment for a non-holonomic robot. To perform such a successful and safe navigation, three controllers realizing, respectively, nominal vision-based navigation, obstacle bypassing and occlusion avoidance have been designed using the task function approach. Then it suffices to sequence them to realize the complete mission. To guarantee the control continuity when switching between two successive controllers, two sequencing approaches have been used and compared. Simulation results validate our work.

International audience; This paper considers the problem of identifying the control torques associated withthe generation of complex movements in an anthropomorphic system. We present a genericmotion generation scheme for humanoid robots. Then we use the torques estimated from humanmotion capture and force sensor measurements, to compare with similar movements simulatedon a humanoid robot. The general features of movement during a sequence of reaching tasks areanalyzed. In particular we compare kinematics-based and dynamics-based movements. Finally,the variation of torques at the different joints are compared and discussed.

Inspired by prestigious institutions (including MIT), this pedagogical project aims to provide an attractive medium for teaching artificial intelligence through interdisciplinary projects and to improve the success of undergraduate and master's students. Indeed, by involving students in projects that let them discover the different subjects taught in their future courses, we want to awake undergraduate students' interest and assist them in building their training project., Inspiré par les pratiques d'établissements prestigieux (notamment au MIT), le projet pédagogique ici présenté vise à fournir un support attractif tel que les robots pour l'enseignement de l'intelligence artificielle au travers de projets interdisciplinaires et à améliorer la réussite des étudiants en Licence et en Master. En effet, en impliquant les étudiants dans des projets leur permettant de découvrir les différentes thématiques enseignées en Master, nous souhaitons intéresser les étudiants de licence et les accompagner dans la construction de leur projet de formation afin qu'il leur corresponde au mieux. L'étude comparative présentée ici a permis d'étudier les effets de l'utilisation de robots en pédagogie de projet sur la motivation et l'investissement des étudiants.

International audience; Jointly working on shared digital artifacts - such as wikis - is a well-tried method of developing knowledge collectively within a group or organization. Our assumption is that such knowledge maturing is an accommodation process that can be measured by taking the writing process itself into account. This paper describes the development of a tool that detects accommodation automatically with the help of machine learning algorithms. We applied a software framework for task detection to the automatic identification of accommodation processes within a wiki. To set up the learning algorithms and test its performance, we conducted an empirical study, in which participants had to contribute to a wiki and, at the same time, identify their own tasks. Two domain experts evaluated the participants' micro-tasks with regard to accommodation. We then applied an ontology-based task detection approach that identified accommodation with a rate of 79.12%. The potential use of our tool for measuring knowledge maturing online is discussed.

Offline robot dynamic identification methods are mostly based on the use of the inverse dynamic model, which is linear with respect to the dynamic parameters. This model is sampled while the robot is tracking reference trajectories that excite the system dynamics. This allows using linear least-squares techniques to estimate the parameters. The efficiency of this method has been proved through the experimental identification of many prototypes and industrial robots. However, this method requires the joint force/torque and position measurements and the estimate of the joint velocity and acceleration, through the bandpass filtering of the joint position at high sampling rates. The proposed new method called DIDIM requires only the joint force/torque measurement, which avoids the calculation of the velocity and acceleration by bandpass filtering of the measured position. It is a closed-loop output error method where the usual joint position output is replaced by the joint force/torque. It is based on a closed-loop simulation of the robot using the direct dynamic model, the same structure of the control law, and the same reference trajectory for both the actual and the simulated robot. The optimal parameters minimize the 2-norm of the error between the actual force/torque and the simulated force/torque. This is a nonlinear least-squares problem which is dramatically simplified using the inverse dynamic model to obtain an analytical expression of the simulated force/torque, linear in the parameters. A validation experiment on a two degree-of-freedom direct drive rigid robot shows that the new method is efficient.

International audience; In the context of task sharing between a robot companion and its human partners, the notions of safe and compliant hardware are not enough. It is necessary to guarantee ergonomic robot motions. Therefore, we have developed Human Aware Manipulation Planner (Sisbot et al., 2010), a motion planner specifically designed for human–robot object transfer by explicitly taking into account the legibility, the safety and the physical comfort of robot motions. The main objective of this research was to define precise subjective metrics to assess our planner when a human interacts with a robot in an object hand-over task. A second objective was to obtain quantitative data to evaluate the effect of this interaction. Given the short duration, the “relative ease” of the object hand-over task and its qualitative component, classical behavioral measures based on accuracy or reaction time were unsuitable to compare our gestures. In this perspective, we selected three measurements based on the galvanic skin conductance response, the deltoid muscle activity and the ocular activity. To test our assumptions and validate our planner, an experimental set-up involving Jido, a mobile manipulator robot, and a seated human was proposed. For the purpose of the experiment, we have defined three motions that combine different levels of legibility, safety and physical comfort values. After each robot gesture the participants were asked to rate them on a three dimensional subjective scale. It has appeared that the subjective data were in favor of our reference motion. Eventually the three motions elicited different physiological and ocular responses that could be used to partially discriminate them.

International audience; In robotics, appearance-based topological map building consists in infering the topology of the environment explored by a robot from its sensor measurements. In this paper, we propose a vision-based framework that considers this data association problem from a loop-closure detection perspective in order to correctly assign each measurement to its location. Our approach relies on the visual bag of words paradigm to represent the images and on a discrete Bayes filter to compute the probability of loop-closure. We demonstrate the efficiency of our solution by incremental and real-time consistent map building in an indoor environment and under strong perceptual aliasing conditions using a single monocular wide-angle camera

International audience; In robotic applications of visual simultaneous localization and mapping, loop-closure detection and global localization are two issues that require the capacity to recognize a previously visited place from current camera measurements. We present an online method that makes it possible to detect when an image comes from an already perceived scene using local shape information. Our approach extends the bag of visual words method used in image recognition to incremental conditions and relies on Bayesian filtering to estimate loop- closure probability. We demonstrate the efficiency of our solu- tion by real-time loop-closure detection under strong perceptual aliasing conditions in an indoor image sequence taken with a handheld camera.

International audience; We present a topological navigation system that is able to visually recognize the different rooms of an apartment and guide a robot between them. Specifically tailored for small entertainment robots, the system relies on vision only and learns its navigation capabilities incrementally by interacting with a user. This continuous learning strategy makes the system particularly adaptable to environmental lighting and structure modifications. From the computer vision point of view, the system uses a purely appearance-based image representation called bag of visual words, without any metric information. This representation was adapted to the incremental context of robotics and supplemented by active perception to enhance performances. Empirical validation on real robots and on the publicly available INDECS image database are presented.

International audience; This paper deals with dynamic situations processing issue. We focus here on the CaseBased Reasoning (CBR). We present the use of this paradigm in the field of assistance to people with disabilities. The objective is to discharge the user from the constraints of a wheelchair control by assisting him in the reproduction of the routes frequently employed. The proposed approach is based on two important steps. The first one consists in recognizing a route followed by the wheelchair based on a similarity measure with each one already carried out. In the second, an algorithm of the new routes learning is proposed so that they are used in the future recognitions. A strategy of case memory maintenance is proposed allowing the improvement of the system performances; L’objectif de ce travail est la reconnaissance de situations dynamiques. L’étude est principalement appliquée à la robotique mobile : le but est d’assister l’utilisateur d’un fauteuil roulant à reproduire les trajets fréquemment employés afin d’éviter de définir à chaque fois les mêmes commandes de directions. Parmi les différentes approches, nous nous intéressons au raisonnement à partir de cas. L’approche proposée repose sur deux étapes importantes. La première étape consiste à reconnaître le trajet emprunté par le fauteuil en se basant sur un calcul de similarité avec ceux qui ont été déjà effectués. Dans la deuxième étape, un algorithme d’apprentissage des nouveaux trajets est proposé pour qu’ils soient utilisés dans les futurs raisonnements. Des stratégies d’organisation et de maintenance de la base de cas sont proposées permettant l’amélioration des performances du système.

International audience; Localization for low cost humanoid or animal-like personal robots has to rely on cheap sensors and has to be robust to user manipulations of the robot. We present a visual localization and map-learning system that relies on vision only and that is able to incrementally learn to recognize the different rooms of an apartment from any robot position. This system is inspired by visual categorization algorithms called bag of words methods that we modified to make fully incremental and to allow a user-interactive training. Our system is able to reliably recognize the room in which the robot is after a short training time and is stable for long term use. Empirical validation on a real robot and on an image database acquired in real environments are presented.

International audience; Most map building methods employed by mobile robots are based on the assumption that an estimate of robot poses can be obtained from odometry readings or from observing landmarks or other robots. In this paper we propose methods to build a global geometric map by integrating scans collected by laser range scanners without using any knowledge about the robots' poses. We consider scans that are collections of line segments. Our approach increases the flexibility in data collection, since robots do not need to see each other during mapping, and data can be collected by multiple robots or a single robot in one or multiple sessions. Experimental results show the effectiveness of our approach in different types of indoor environments

International audience; The aim of this paper is to detect and follow the pipeline in sonar imagery. This work is performed in two steps. The first is to split an image (first experiment) or an transformed line image of pipeline image (second experiment) into regions of uniform texture using the Gray Level Co-occurrence Matrix Method (GLCM). The second addresses the unsupervised learning method based on the Artificial Neural Networks (Self-Organizing Map or SOM) used for determining the comparative model of pipeline from the image. To increase the performance of SOM, we propose a penalty function based on data histogram visualization for detecting the position of pipeline. After a brief review of both techniques (GLCM and SOM), we will present our methods and some results from several experiments on the real world data set

[Notes_IRSTEA]bibl. [Departement_IRSTEA]GEAPA [TR1_IRSTEA]42 - ALITECH / CAPORAL; International audience; This paper proposes a way to achieve positioning tasks by visual servoing, for any orientation of the camera, when the desired image of the observed object cannot be precisely described. The object is assumed to be planar and motionless but no knowledge about its shape or pose is required. To simplify the problem, first, we treat the case of a threadlike object and then we show how our approach can be generalized to an object with three particular points. The control law is based on the use of 2d visual servoing and on an estimation of a 3d parameter. Experimental results relative to objects of unknown shape are given to validate the approach. In addition, an algorithm to estimate the depth between the object and the camera is provided which leads to the dimensions of the object.

International audience; Since image-based visual servoing is a local feedback control solution, it requires the definition of intermediate subgoals in the sensor space at the task planning level. In this paper, we describe a general technique for specifying and tracking trajectories of an unknown object in the camera image space. First, physically valid C2 image trajectories which correspond to quasi-optimal 3D camera trajectory (approaching as much as possible a straight line) are performed. Both mechanical (joint limits) and visibility constraints are taken into account at the task planning level. The good behavior of Image-based control when desired and current camera positions are closed is then exploited to design an efficient control scheme. Real time experimental results using a camera mounted on the end effector of a six d-o-f robot confirm the validity of our approach.