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International audience; The development, in the last decades, of technologies for precision agriculture allows the acquisition of crop data with a high spatial resolution. This offers possibilities for innovative control and raises new logistics issues that may be solved using discrete event models. In vineyards, some technologies make it possible to define zones with different qualities of grapes and sort the grapes at harvest to make different vintages. In this context, the Differential Harvest Problem (DHP) consists in finding a trajectory of the harvesting machine in the field in order to obtain at least a given quantity of higher quality grapes and minimising working time. In available literature, the DHP has been solved using Constraint Programming. In this paper, we investigate if it is possible to solve the DHP using the Cost Optimal Reachability Analysis feature of a model-checking tool such as UPPAAL-CORA. A model named DHP_PTA has been designed based on the priced timed automata formalism and the UPPAAL-CORA tool. The method made it possible to obtain the optimal trajectory of a harvesting machine for a vine plot composed of up to 14 rows. The study is based on real vineyard data. This paper is an extended version of a communication presented at WODES 2018 (Saddem-Yagoubi IFAC-PapersOnLine 51(7):57-63, 2018).

International audience; Robotic systems evolving in hazardous and harsh environment are prone to mission failure or system loss in presence of faults. This paper presents a fault tolerant methodology, implemented into a control architecture of an underwater robot that executes biological monitoring missions. High level constraint violations (mission, safety, energy, time and localization) and low level faults (software and hardware faults) are considered using a method based on fault trees. These undesirable events are detected and treated by a fault tolerant module that decides to recover at low level or to give a feedback to the mission manager which selects the high level reaction. This fault tolerant architecture has been tested on real field conditions, and we illustrate our methodology on a set of selected events. We conclude about reliability improvement of low cost underwater robots for complex and long missions.

Energy is a key feature that must be explicitly managed for long-term autonomous robotic missions. Many research studies have addressed the energy issue, developed energy-aware motion control or integrated energy in mission objectives. However, few studies have comprehensively assessed the impact of software and hardware choices on power consumption of robots. Based on experimental analysis and according to the selected control scheme and hardware configuration, this paper proposes energy consumption models for the Pioneer 3DX. The proposed models highlight the existence of an optimal velocity that minimizes motion energy. These models are experimentally evaluated and discussed.

International audience; In this paper, we present an approach to test underwater robots with a mission perspective. We propose five classes of oracle mission properties, used to perform test verification and evaluation: mission phases, time, energy, safety and localization. We study how these properties can be used, using data from the generated logs and analyzing the set of measurements. We apply this methodology on our semi-AUV prototype which executes autonomously biologic observation protocols in the Mayotte lagoon. For that we use an offline oracle property checker, and we focus on the issues of test acceptance criteria and ground truth despite low cost localization sensors. Results and lessons learned from this experiment are presented.

International audience; The development, in the last decades, of technologies for precision agriculture allows the acquisition of crop data with a high spatial resolution. This offers possibilities for innovative control and raises new logistics issues that may be solved using discrete event models. In vineyards, some technologies make it possible to define zones with different qualities of grapes and sort the grapes at harvest to make different vintages. In this context, the Differential Harvest Problem (DHP) consists in finding a trajectory of the harvesting machine in the field in order to obtain at least a given quantity of higher quality grapes and minimising working time. In available literature, the DHP has been solved using Constraint Programming. In this paper, we investigate if it is possible to solve the DHP using the Cost Optimal Reachability Analysis feature of a model-checking tool such as UppAal-CORA. A model named DHP PTA has been designed based on the priced timed automata formalism and the UppAal-CORA tool. The method made it possible to obtain the optimal trajectory of a harvesting machine for a vine plot composed of up to 12 rows. The study is based on real vineyard data.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE [ADD1_IRSTEA]Équiper l'agriculture; International audience; Precision agriculture is a set of methods based on spatial and timed information which aims at making agricultural operations specific to local crop needs. This study was conducted to contribute to precision spraying for trellised perennial crops such as grapevine with a new method called Automata Modelling for Precision Spraying (AMPS). AMPS is based on the timed automata formalism and the UppAal-CORA model-checking tool with cost optimisation. It takes 2D ground-based LiDAR data of the canopy as input and computes a command sequence for the sprayer that is optimized for a cost criterion. AMPS was tested on LiDAR data from a vine row and with a hypothetical sprayer model based on pneumatic technology and individual command for each spout. The chosen cost criterion was the amount of product sprayed on the row. It was demonstrated on the example that a significant proportion of phytosanitary product can be saved. It was also shown that it is necessary to take into account spout control dynamics, because the savings are inferior to the ideal case in which spout response would be instantaneous.

International audience; Mobile automated systems, such as robots or machinery for precision agriculture, may be designed to perform actions that vary in space according to information from sensors or to a mission map. To be reliable, the design process of such systems should involve the combined verification of spatial and dynamic properties. We consider here CTL model-checking of a mobile robot's behavior, using the UppAal Timed Automata verifier. We consider reachability properties including path finding. Space is modeled as a 2D grid and the mobile robot path is unknown a priori. In this case, the exhaustive state space exploration of model-checking leads to the generation of many possible movements. This exposes such model-checking to combinatorial issues depending on the grid size and the complexity of system dynamics. In this paper, we propose a decomposition methodology reducing the memory requirements for the verification task. The decomposition is twofold. The grid is decomposed in sub-grids and the model-checking query on the whole grid is decomposed in a set of queries on the sub-grids. A set of test cases and check the validity of the decomposition concept. The decomposition methodology is compared to a simpler method that verifies the reachability property without proceeding to decomposition.

International audience; The research presented is a contribution to the development of command methods for vine sprayers in order to optimize spraying according to the vegetation. The question was: considering the control dynamics of a sprayer, is it possible to apply a previously determined map of pesticide dose and sprayer control set points?

International audience; Real long-term, complex and autonomous mission is still a challenge for robotics. This paper presents an efficient approach enhancing the robot with fault tolerance. It uses performance viewpoints to guide hardware and software resources allocation all along the mission according to faults effects and detection. Simulated and experimental results are proposed and analyzed.

International audience; Mission performance is a large concept. It is rarely addressed in the context of autonomous mobile robotics. This paper proposes a generic framework addressing the concept of performance for autonomous mobile robotic mission. Moreover it presents an approach to manage the mobile robot hardware and software resources during the mission execution according to performance objectives. Simulation results illustrate the proposed approach on a patrolling mission example.

International audience; One of the crucial questions to develop Autonomous Mobile Robotic systems is the energy consumption, its monitoring and management all along the mission. Mission complexity and fault tolerance capabilities require to exploit system redundancies, in terms of algorithms and hardware recruitment. This choice has an evident impact on energy consumption. This paper proposes an identification protocol to establish the energy consumption models for each control configuration of a Pioneer 3DX. These models are destined to be used as online pre-dictors providing an estimation of the necessary remaining energy that mission success 'nominally' requires. At the end, the proposed energy consumption models are validated and discussed experimentally.

Experience demonstrates that autonomous mobile robots running in the field in a dynamic environment often breakdown. Generally, mobile robots are not designed to efficiently manage faulty or unforeseen situations. Even if some research studies exist, there is a lack of a global approach that really integrates dependability and particularly fault tolerance into the mobile robot design.This paper presents an approach that aims to integrate fault tolerance principles into the design of a robot real-time control architecture. A failure mode analysis is firstly conducted to identify and characterize the most relevant faults. Then the fault detection and diagnosis mechanisms are explained. Fault detection is based on dedicated software components scanning faulty behaviors. Diagnosis is based on the residual principle and signature analysis to identify faulty software or hardware components and faulty behaviors. Finally, the recovery mechanism, based on the modality principle, proposes to adapt the robot's control loop according to the context and current operational functions of the robot.This approach has been applied and implemented in the control architecture of a Pioneer 3DX mobile robot. Autonomous mobile robotics fails to carry out complex mission in dynamic environment.Presentation of a global fault tolerant methodology enhancing robots dependability.FMECA fault forecasting and failure detection using dedicated software modules.Diagnosis based on signature analysis and recovery using autonomy level adaptation.Implementation and experiments of these concepts in a real-time control architecture.

This paper presents some of the results of a CNRS research project aiming at analysing an emerging field of the decision-aid: decision support systems applied to enterprise change management. Our objective is to develop an in-depth analysis of industrial needs and research perspectives on this focus. After a overall presentation of the methodology and scientific positioning of the project, we will synthesise the results of a national survey concerning industrial needs. Then, we will suggest a global structure of this research field and explain the most important trends. This paper emphasises perspectives emerging from the potential complementarities between qualitative and quantitative approaches of enterprise management.

The concurrent engineering approach seems to be a new way to minimise cost and delay for product design. However, few experiments using distributed skills are described in the literature. This paper describes a concurrent engineering experiment involving four French academic laboratories, to design an automated assembling bank for an aeroplane fuselage. The chosen concurrent design process is described first. Then, all the communications accomplished within the 2 years of the project and their protocols are described. From their study, the cooperation involved is modelled and analysed using the concept of the cooperation graph. This experiment produces advice on how to succeed in a concurrent engineering project.

This paper presents an approach allowing to estimate the performance of enterprise processes. Many areas of performance estimation can be studied (temporal, quality, ... ). This approach takes into account the entities which can influence the performance of an enterprise (particularly human actors) through their characteristics. Mathematical laws allow to compose these influences for the studied areas. The proposed approach is used on a real industrial process.

Presently, in a company, the design process is more and more distributed and involves many activities which are shared out among different actors. This kind of work organisation requires to perfectly identify and manage the design process decisions and cooperations. In this paper, we propose an approach to identify and evaluate decisional process. At first, we present the organisation of the project and a quantative overview on the cooperations. Then we propose a method based on the graph theory to identify which kind of cooperation exist between actors during the design process. Finally an example shows the interest of this work

International audience; La robotique est par essence multidisciplinaire, traitant dès leur origine des problèmes couplant mécanique, automatique, électronique, informatique, etc. sans omettre ceux relatifs au domaine d’application lui-même. Elle doit ses progrès aux avancées réalisées dans chaque discipline ainsi qu’à leur croisée. Les robots sont des entités technologiques de plus en plus complexes auxquelles sont confiées des missions toujours plus compliquées, relevant d’une multitude de domaines applicatifs. Les spécificités des divers domaines d’application et des grandes catégories de robots (robotique terrestre, sous-marine, aérienne) sont souvent à l’origine de solutions différentes. Certaines applications vont requérir une réactivité importante et des capacités décisionnelles moindres, d’autres auront des besoins de planification importants, etc.Cette complexité induit de nombreuses exigences, notamment sur l’informatique censée gérer le fonctionnement du robot et supporter ses capacités d’action, d’adaptation, de décision, etc., cette « intelligence » que lui confère son contrôle. C’est donc de l’architecture logicielle de contrôle, c’est-à-dire la manière dont est conçu et développé le logiciel chargé du contrôle du robot, dont nous allons discuter dans cet article.Ces architectures logicielles se distinguent par le besoin de prendre en compte tout un spectre de fonctions allant de calculs délibératifs, très gourmands en temps et en espace, jusqu’au contrôle en temps réel de dispositifs physiques. Organiser ces « fonctions », les mettre en relation requiert un niveau d’expertise élevé. C’est pourquoi des solutions générales ont initialement été proposées sous la forme de « modèles architecturaux ». Les modèles architecturaux classiquement admis seront présentés, sachant qu’ils sont encore soumis à évolution pour intégrer la variété de schémas relationnels qui donnent une dimension unique à ces architectures. En effet, le robot immergé dans son environnement est aussi sujet à des relations homme-robot (autonomie décisionnelle partagée), robot-robot (flottille) ou encore robot-environnement actif (capteurs de l’habitat et routes intelligentes par exemple) qui, déclinées sur le plan des architectures de contrôle, nécessitent de considérer les relations dynamiques qui peuvent s’instaurer.Si le modèle architectural guide dans la manière de structurer une architecture, il reste à définir comment la décrire et la mettre en œuvre. Avec la croissance de la complexité des architectures logicielles robotiques et l’explosion de la diversité toujours plus grande des applications et des missions, la conception et le développement d’architectures logicielles performantes et correctes devient un enjeu majeur. Il n’y a à ce jour aucune approche communément admise pour capitaliser et mutualiser les connaissances et les bonnes pratiques et pour réutiliser les briques logicielles développées. L’état des lieux que nous allons dresser témoigne de la diversité des propositions, révélant l’influence des cultures initiales des concepteurs, plus robotique, automatique ou informatique. Dans tous les cas, ces propositions visent, avec plus ou moins de succès, à définir comment décrire et encapsuler les diverses fonctions que le robot doit assurer sous la forme d’un ensemble d’entités logicielles en interaction. Ce faisant, l’objectif est de conférer à la solution des propriétés de modularité, de portabilité, de réutilisabilité, etc.Décrire l’architecture logicielle n’est pas suffisant car il faut ensuite l’implémenter, la déployer et l’exécuter. Implémenter l’architecture logicielle et la déployer sur une cible d’exécution, tout en maîtrisant les contraintes logiques et temporelles de l’exécution typiques des systèmes réactifs, conduisent à considérer les contraintes provenant de la plate-forme (matérielle, système d’exploitation, langages de programmation) sous-jacente. Construire des architectures pérennes, réutilisables et adaptables pour une grande variété de plateformes et de composants physiques (capteurs, actionneurs, mais aussi processeurs, réseaux, et autres matériels parfois spécifiques à la robotique) constitue un défi important. Nous évoquerons dès lors, à travers la présentation des approches récentes, les intergiciels (appelés « middleware ») pour les architectures de contrôle robotiques tant leur rôle peut être primordial à ces égards.

This paper presents an approach well-suited to model and analyse behaviour of complex industrial systems confronted with hazardous events. An industrial complex system (process or factory organisation) is described using several entities and relations. The obtained model will be translated into Petri Nets for structural analysis and into Interpreted Sequential Machine for verifying temporal and dynamic properties. This composite approach has been developed within a common research project for the control of hazardous events in production systems.

International audience; This paper presents how autonomy adaptation can be useful to enhance the fault tolerance of autonomous mobile robots. For that, we proposed a global and structured methodology which allows integrating specific fault tolerant mechanisms into an adaptive control architecture. When a problem is detected, the autonomous behavior of the robot is automatically adapted to overcome it. The human operator can punctually or definitively be inserted in the control loop to replace the damaged functionalities and to ensure the success of the mission. Experimental results on a mobile robot are proposed to illustrate the autonomy adaptation.

International audience; Afin de préparer les futurs techniciens supérieurs aux réalités technologiques de l'informatique industrielle, le département GEII de l'IUT de Montpellier propose en 1ère et 2nde année de formation, l'étude et la mise en oeuvre d'un support matériel développé autour du PIC18F452. Cet article présente un projet couvrant la plupart des objectifs et no-tions d'Informatique Industrielle apparaissant dans le Programme Pédagogique National du DUT GEII. Le contenu s'adresse donc à un public en formation BAC+1 et BAC+2 désireux de se familiariser avec l'environnement des micro-contrôleurs de la famille PIC18. Le projet est riche en termes de notions abordées : il nécessite donc une présentation progressive et détaillée afin de faciliter l'acquisition de ces notions.

National audience

International audience; This paper details the development of an adaptive control architecture permitting to improve the reliability and robustness of autonomous mobile robot. A continuous monitoring of the significant failures allows dynamically choosing the most relevant reaction ensuring the success of the mission. This adaptive behavior is implemented into the control architecture COTAMA. The key points of the specific mechanisms added to COTAMA are addressed and explained. Experimental results are proposed to illustrate the control architecture adaptive behavior.

Managing change projects in manufacturing enterprises remains difficult and often risky. Some existing research works, good practices and available tools are poorly adapted or hard to autonomously use by industrial decision makers themselves. This article presents and illustrates a change management aided decision approach allowing the construction and evaluation of different possible change projects while taking a given enterprise strategy into account. First, the enterprise is described by using a cross reference to systemic and enterprise modelling approaches. Secondly, the current state of the enterprise is characterized and evaluated from different enterprise performance viewpoints. Thirdly, operational methods are modelled to improve reactivity, flexibility, interoperability and so on, while respecting the behavioural constraints and performance indicator impacts, thus facilitating the building, evaluation and comparison of different change project solutions. Fourthly, this approach is implemented using a methodology and supporting tool.

National audience; This paper presents a set of mechanisms allowing the detection of control architecture inconsistencies, in the context of autonomous mobile robotics. This approach integrates an observation level into the structure of the control architecture to monitor and analyze the internal state of the robot and detect inconsistencies. These data are processed and the most pertinent information are sent to the Human supervisor and/or to a decision level which can adjust the robot autonomy according to the identified problem. These mechanisms have been implemented using architectural concepts previously developed at LIRMM. Based on these developments, adaptive hybrid control architecture is currently under development.

National audience

The problem of change management in very complex and unstable environment is still not often tackled, despite a real need from the industrial stakeholders. This article proposes a three-step change management aided decision approach. Firstly the enterprise is described using a systemic approach using the Sagace framework. Secondly, the state of the enterprise system is characterized and evaluated using three classes of performance indicators for enterprise control, adaptation and anticipation viewpoints. Finally modelling production management methods makes possible to build the change trajectories which, from state to state, lead to the desired performance objectives. This approach which is still in the development and evaluation phase is illustrated through a didactic example.

International audience; In a changing environment, the human factor is a key element to ensure the survival of an enterprise. It is hence necessary to model and analyse the enterprise processes with regard to both human and material resources. A French approach to process performance and its relation to the competence concept are presented. Several studies in which competence is integrated in the estimation of process performance are presented, and the method developed is described. It integrates individual and collective competencies to estimate the performance of an activity. This is first achieved in a specific case and, then generalized and formalized for different viewpoints. Finally, some new studies in which the proposed method was used are pointed out.

International audience; Face à un environnement très versatile, la gestion du changement est une problématique encore peu abordée du pilotage de l'entreprise. Après avoir montré sa pertinence et rappelé les principaux travaux menés en sciences de gestion et en génie industriel une démarche d'aide à la décision pour la conduite du changement est proposée. Celle-ci s'appuie d'une part sur une approche systémique de modélisation du système entreprise complétée par une caractérisation de l'état de ce dernier essentiellement par ses dimensions de performance, stabilité et intégrité. Afin d'identifier les trajectoires d'évolution envisageables cette démarche est d'autre part complétée par une modélisation des méthodes de gestion de production à travers leurs conditions d'application et leurs impacts estimés. Afin d'en assurer la cohérence, un modèle unifié intégrant les principaux concepts nécessaires au déploiement de l'approche est présenté.

International audience

International audience; It becomes important to model and analyse the enterprise processes with regard to both human and material resources. This paper presents a method developed in the frame of an industrial project, to integrate individual and collective competence to estimate the performance of an activity of a process.