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International audience; We consider feedback control systems where sensor readings and actuator commands may be compromised by an attacker intending to damage the system. We study this problem at the supervisory layer of the control system, using discrete event systems techniques. The attacker can edit the outputs from the sensors of the system before they reach the supervisory controller as well as it can edit actuator commands before they reach the system. In this context, we formulate the problem of synthesizing a supervisor that is robust against a large class of edit attacks on the sensor readings and actuator commands. Intuitively, we search for a supervisor that guarantees the safety of the system even when sensor readings and actuator commands are compromised. Given the similarities of the investigated problem to the standard supervisory control problem, our solution methodology reduces the problem of synthesizing a robust supervisor against deception attacks to a supervisory control problem. This new and intuitive solution methodology improves upon prior work on this topic.

International audience; Software-Defined Network (SDN) technology provides the possibility to turn the network infrastructure into a dynamic programmable fabric capable of meeting the application needs in real-time. Thanks to the independence of the control plane from the data plane, the control entity, generally called as controller, has also the flexibility to implement proprietary complex algorithms. Within such a dynamic and complex environment, this document advocates for applying formal verification methods and more precisely composition model checking to ensure the correct behavior of the overall SDN system at design phase. To illustrate this purpose, it proposes to build different comprehensive formal models of a typical SDN platform selected here as a study object. Thorough performance results related to each model are provided and discussed. Thanks to such formal verifications, it is possible to pinpoint issues such as the one regarding network isolation within a complex SDN architecture. Although dealing with formal methods, this document attempts to strike a balance between theory, experimental work and network architecture discussion.

International audience; This paper presents a new strategy of supervisory control applied to heating room system that is able to adapt to different operating conditions, in order to reduce the energy consumption and guaranteed a good thermal comfort for the occupants. The aim is to design a multi-model and multi-controller supervisor by using neural networks with a view to overcome the limitations of using a single controller and to deal with nonlinearities, parameters uncertainties and the time constant of the heating system. The proposed methodology is based on three model/controller pairs, a monitoring signal generator and a switching logic. Three architectures of neural network architectures, namely multilayer perceptron neural networks, radial basis function and memory neuron networks are used to evaluate this control technique and to design the different controller/model pairs which correspond to the same work office and a specific isolation state. A comparative study is associated to this work in order to recognize the best neural network in terms of performance and simulation time. The results obtained for three scenarios addressed herein show the importance and the effectiveness of this method.

International audience; In discrete-event systems, the opacity of a secret ensures that some behaviors or states cannot be inferred with certainty from partial observation of the system. Enforcing opacity in a discrete-event system, encoded by a finite labelled transition system (LTS), is a way to avoid information leakage. Checking opacity is decidable but costly (EXPTIME in the worst cases). This paper addresses opacity for modular systems in which every module, represented by an LTS, has to protect its own secret (a set of secret states S) w.r.t. a local attacker. Once the system is composed, we assume a coalition between the attackers that share their local view (called the global attacker). Assuming the global attacker can observe all interactions between modules, we provide a reduced-complexity opacity verification technique and an algorithm for constructing local controllers that enforces opacity for each secret separately.

International audience; In situ synthesis of topologically modified linear polyethylenes (PE) using single-site polymerization catalysis is a challenging task, but it can enable the production of valuable advanced polymer materials with tailored properties. Described herein is an investigation aimed at the efficient generation of long-chain branches (LCB) in linear PEs using Al-alkenyl species, namely, iBuAl(oct-7-en-1-yl)2 (Al-1), in combination with homogeneous rac-{EBTHI}ZrCl2 (Zr-1)/MAO or heterogeneous MAO on silica-supported-rac-{EBTHI}ZrCl2 (supp-Zr-1)/TIBAL catalytic systems. As corroborated by extensive rheological studies and 13C NMR spectroscopy, the Al-alkenyl reagent was found to be quite efficient in the formation of LCB, via a mechanistic pathway involving both insertion and transmetallation reactions. Formation of LCB has been rationalized by density functional theory (DFT) computations carried out on the putative [rac-{EBTHI}Zr-R]+ (R = Me, nPr, and pentyl) cationic species and including a solvent model. Of the three possible isomers of Al/Zr heterobimetallic complexes derived from the cationic species [rac-{EBTHI}Zr-R]+ and Al-1, only one was identified, on kinetic and thermodynamic grounds, as the key intermediate. The DFT study also unveiled that (i) insertion of ethylene into the Zr-alkyl bond of the growing PE chain is accompanied by a reversible decoordination of the Al-vinyl transfer agent (AVTA), (ii) the vinyl 1,2-coordination/insertion of the alkenyl moieties of Al-1 into the Zr-alkyl bond, resulting in the formation of branching, is in direct kinetic competition with the insertion of ethylene, and (iii) the recoordination of the AVTA after either insertion step is thermodynamically favored and mostly responsible for the transmetallation phenomenon.

International audience; In order to put in a prominent position positive and negative points about human- machine interfaces in a supervisory control room, « fast » evaluation methods (or so-called discount evaluation methods) can be used. One of these, based on guidelines, is presented in this paper. It is based on a questionnaire guiding the analysis. It has been applied to study a control room of a chemical process.

International audience; Cybersecurity in Industrial Control Systems (ICS) is a crucial problem, as recent history has shown. A notable characteristic of ICS, compared to Information Technology, is the necessity to take into account the physical process, and its specific dynamics and effects on the environment, when considering cybersecurity issues. Intrusion Detection Systems have been studied extensively. In our work, we address the less classic topic of response mechanisms, and their automation in a self-protection feedback loop. More precisely, we address self-protection seen as resilience, where the functionality of the system is maintained under attacks, be it in a degraded mode. We model this as a Discrete Event Systems supervisory control problem, involving a model of the plant's possible behaviors, a model of considered attacks, and a formulation of the control objectives. We consider a case study, and perform a prototype implementation and simulation, using the Heptagon/BZR programming language and compiler/code generator, and targeting a multi-PLC experimental platform.

As any other infrastructure relying on cyber-physical systems (CPS), naval CPS are highly interconnected and collect considerable data streams, on which depend multiple command and navigation decisions. Being a data-driven decision system requiring optimized supervisory control on a permanent basis, it is critical to examine the CPS vulnerability to anomalies and their propagation. This paper presents an approach to detect CPS anomalies and estimate their propagation applying a quality assessed graph, which represents the CPS physical and digital subsystems, combined with system variables dependencies and a set of data and information quality measures vectors. Following the identification of variables dependencies and high-risk nodes in the CPS, data and information quality measures reveal how system variables are modified when an anomaly is detected, also indicating its propagation path. Taking as reference the normal state of a naval propulsion management system, four anomalies in the form of cyber-attacks – port scan, programmable logical controller stop, and man in the middle to change the motor speed and operation of a tank valve – were produced. Three anomalies were properly detected and their propagation path identified. These results suggest the feasibility of anomaly detection and estimation of propagation estimation in CPS, applying data and information quality analysis to a system graph.

International audience; Nowadays, communication and web services are part of our lives, including education, and e-learning applications are used more and more. However, teaching in engineering sciences requires an important amount of practical experiments. Hence, remote laboratories are an attractive solution, offering new tools for both teachers and learners. Our objective is to propose a fully open source remote laboratory for generic practice, in all fields of engineering education or applied sciences. This work is based on an open source Supervisory Control and a Data Acquisition platform programmed with Python. Interoperability is one of the main issues considered here to ensure a wide compatibility with multi-communication protocols and multi-instruments used in practical labwork

We consider feedback control systems where sensor readings may be compromised by a malicious attacker intent on causing damage to the system. We study this problem at the supervisory layer of the control system, using discrete event systems techniques. We assume that the attacker can edit the outputs from the sensors of the system before they reach the supervisory controller. In this context, we formulate the problem of synthesizing a supervisor that is robust against a large class of edit attacks on the sensor readings. We solve this problem using a new methodology that improves upon prior work on this topic. The solution methodology is based on the solution of a partially observed supervisory control problem with arbitrary control patterns. We also provide results on the existence of a supremal robust supervisor.

Wireless Sensor networks are attracted many activities of research and development during the last decade. Yet, the distributed behavior of a WSN remains centered on two main objectives: sensing and routing. This thesis advocates the introduction of an additional feature, which can be considered interesting from a functional point of view and potentially from the power consumption one: starting from a designer-specified requirement, implement a multiple level synergy between (groups of) nodes, based on adequate interaction. This is achieved by automatic generation and distribution of correct-by-construction code, relying on the Supervisory Control Theory. The Discrete Controller Synthesis (DCS) technique is an application of this theoretic framework. In this thesis, we show how DCS can be used for WSN. Thus, its potential is at two levels. The intra-cluster scheduling of a redundant group of sensors with specifications expressing the mutual exclusion during the activation of a sensor within a cluster, essential to save the energy within the network and then a multicriteria automatic generation of an optimal routing functionality. Specifically, an optimal path should have both a minimal length and go through nodes having maximal residual energy. The cited formal tools lean on a modelling approach based on communicating finite state machines (CFSM). The scientific challenges are generally related to the nature of the WSN as well as to its size. The DCS can only generates a monoblock controllers, while the WSN’s behavior is essentially distributed. The issue is how to distribute a global controller, who appears in the form of a logical constraint expressed on the global state of the network, into local controllers while adding the necessary synchronization to guarantee a distributed functioning equivalent to the initially generated controller.; Les réseaux de capteurs sans fil ont attiré beaucoup d’activités de recherche et développement au cours de la dernière décennie. Pourtant, leur utilisation est restreinte, à ce jour, à la surveillance et l’acheminement des informations détectées. Cette thèse vise à introduire un nouvel aspect intéressant de point de vue fonctionnel. Partant d’une exigence spécifiée initialement, mettre en oeuvre une synergie à plusieurs niveaux entre un ensemble des noeuds, tout en se basant sur une interaction adéquate. Ceci est réalisé par la génération automatique de code (correct par construction) et sa distribution par la suite en s’appuyant sur la théorie de contrôle par supervision. La synthèse de contrôleurs discrets SCD est une application de ce cadre théorique. Dans ce manuscrit, nous montrons comment la technique de la SCD peut être utilisée dans le domaine de réseaux de capteurs sans fil. Ainsi son potentiel se décline à deux niveaux. L’ordonnancement intra-cluster (groupe redondant de capteurs) avec des spécifications exprimant l’exclusion mutuelle lors de l’activation d’un capteur au sein d’un cluster, essentielle pour économiser l’énergie du réseau ainsi que la génération automatique d’un algorithme de routage optimal et multicritères pour les réseaux de capteurs. Spécifiquement, un chemin optimal devrait avoir à la fois une longueur minimale en termes de distance tout en évitant des chemins composés de noeuds dits « maillons faibles » (ayant un niveau d’énergie plus bas que la majorité). Les outils formels cités s’appuient sur une démarche de modélisation basée sur des machines à états finis communicantes. Les verrous scientifiques sont liés à la nature d’un réseau de capteurs ainsi qu’à sa taille. La SCD génère des contrôleurs monobloc, alors qu’au sein d’un réseau de capteurs le traitement est essentiellement distribué. La problématique est celle de la distribution d’un contrôleur global, qui se présente sous forme d’une contrainte logique exprimée sur l’état global du réseau, sur chacun des noeuds du réseau, en ajoutant la synchronisation nécessaire pour garantir un fonctionnement distribué équivalent au contrôleur initialement généré.

Wireless Sensor networks are attracted many activities of research and development during the last decade. Yet, the distributed behavior of a WSN remains centered on two main objectives: sensing and routing. This thesis advocates the introduction of an additional feature, which can be considered interesting from a functional point of view and potentially from the power consumption one: starting from a designer-specified requirement, implement a multiple level synergy between (groups of) nodes, based on adequate interaction. This is achieved by automatic generation and distribution of correct-by-construction code, relying on the Supervisory Control Theory. The Discrete Controller Synthesis (DCS) technique is an application of this theoretic framework. In this thesis, we show how DCS can be used for WSN. Thus, its potential is at two levels. The intra-cluster scheduling of a redundant group of sensors with specifications expressing the mutual exclusion during the activation of a sensor within a cluster, essential to save the energy within the network and then a multicriteria automatic generation of an optimal routing functionality. Specifically, an optimal path should have both a minimal length and go through nodes having maximal residual energy. The cited formal tools lean on a modelling approach based on communicating finite state machines (CFSM). The scientific challenges are generally related to the nature of the WSN as well as to its size. The DCS can only generates a monoblock controllers, while the WSN’s behavior is essentially distributed. The issue is how to distribute a global controller, who appears in the form of a logical constraint expressed on the global state of the network, into local controllers while adding the necessary synchronization to guarantee a distributed functioning equivalent to the initially generated controller., Les réseaux de capteurs sans fil ont attiré beaucoup d’activités de recherche et développement au cours de la dernière décennie. Pourtant, leur utilisation est restreinte, à ce jour, à la surveillance et l’acheminement des informations détectées. Cette thèse vise à introduire un nouvel aspect intéressant de point de vue fonctionnel. Partant d’une exigence spécifiée initialement, mettre en oeuvre une synergie à plusieurs niveaux entre un ensemble des noeuds, tout en se basant sur une interaction adéquate. Ceci est réalisé par la génération automatique de code (correct par construction) et sa distribution par la suite en s’appuyant sur la théorie de contrôle par supervision. La synthèse de contrôleurs discrets SCD est une application de ce cadre théorique. Dans ce manuscrit, nous montrons comment la technique de la SCD peut être utilisée dans le domaine de réseaux de capteurs sans fil. Ainsi son potentiel se décline à deux niveaux. L’ordonnancement intra-cluster (groupe redondant de capteurs) avec des spécifications exprimant l’exclusion mutuelle lors de l’activation d’un capteur au sein d’un cluster, essentielle pour économiser l’énergie du réseau ainsi que la génération automatique d’un algorithme de routage optimal et multicritères pour les réseaux de capteurs. Spécifiquement, un chemin optimal devrait avoir à la fois une longueur minimale en termes de distance tout en évitant des chemins composés de noeuds dits « maillons faibles » (ayant un niveau d’énergie plus bas que la majorité). Les outils formels cités s’appuient sur une démarche de modélisation basée sur des machines à états finis communicantes. Les verrous scientifiques sont liés à la nature d’un réseau de capteurs ainsi qu’à sa taille. La SCD génère des contrôleurs monobloc, alors qu’au sein d’un réseau de capteurs le traitement est essentiellement distribué. La problématique est celle de la distribution d’un contrôleur global, qui se présente sous forme d’une contrainte logique exprimée sur l’état global du réseau, sur chacun des noeuds du réseau, en ajoutant la synchronisation nécessaire pour garantir un fonctionnement distribué équivalent au contrôleur initialement généré.

International audience; We consider the stabilization problem for linear systems of balance laws subject to uncertain gains affecting the boundary conditions and the reaction term. The stabilization is achieved using the supervisory control, a well established approach in finite dimension. In the context where a controller exists for each estimator, the supervisory control with a performance signal built with the boundary output effectively steers the system to the origin. This novel approach is illustrated with a traffic flow control problem modelled by the Aw-Rascle-Zhang equations.

The supervisory control is a common theory for the synthesis of Petri net (PN) supervisors for discrete event systems given a PN model and a control specification for the maximum permissive behaviour. The theory of regions as one of control synthesis method generates a PN controller to satisfy the control specification. Though the theory of regions has for over a decade received a considerable attention in academy, still very few applications exist. The real cause of this seems to be a contradiction between the abstract controller and its physical implementation. This is evident in particular when the implementation is supposed to be based on a programmable logic controller (PLC), as is the case for flexible manufacturing systems. Indeed, since the synchronous PLC is based on signals, the PN supervisor remains asynchronous; this explains its implementation difficulty. In this work, a control synthesis method using the theory of regions is implemented with a Java application on PLCs of a flexible manufacturing system (FMS) installed in our research laboratory in the University of Lorraine in Metz, France.

Several formal methods of supervisory control of discrete events systems (DES), based on Petri nets (PN) have been developed. However, they are partially structural because of the need to construct the marking graph, which is an automaton, to determine the states forbidden by the specification. Some of those methods are limited to a particular class of Petri nets. Our work focused on the labeled Petri nets (LPN), which offers a better structure for defining the languages and automata. Among the based methods based on Petri nets, the invariant place method (simple and efficient) is the most used, although it does not guarantee in the general an optimal solution. In order to overcome this problem, we have developed a completely structural method, without construction of the marking graph for ordinary labeled Petri nets. It consists in determining in a way structural, admissible constraints for the invariant method place. It is based on the structural condition of controllability of closed loop SED LPN states, got by synchronous product of the process and specification LPN. In addition, we have proved that the structural condition of controllability, defined by the marking condition of entrance places of an uncontrollable synchronous transition, is equivalent to the condition of controllability defined by the languages of the LPN. This condition defines the equation of a separator hyperplan which ensures separation of the admissible states from the forbidden states in the SED. Constraints derived from hyperplane separator are admissible and can be simplified systematically. They provide a one-to-one link between the theory of supervisory control of Ramadge and Wonham and the calculation of maximum permissive controller by the invariant place method. Although for some complex structures (great scale), the maximum permissive solution cannot be guarantee directly; our approach gave the optimal controller in the real case studies considered., Plusieurs méthodes formelles de commande par supervision des systèmes à événements discrets (SED) basées sur les réseaux de Petri (RdP) ont été développées. Cependant, elles sont partiellement structurelles à cause de la nécessité de construire le graphe de marquage, qui est un automate, pour déterminer les états interdits par la spécification. Certaines de ces méthodes sont limitées à une classe particulière de RdP. Notre travail s'est focalisé en particulier sur le RdP synchronisé (RdPS), qui offre une meilleure structure pour définir les langages et les automates. Parmi les méthodes basées sur les RdP, la méthode des invariants (simple et efficace) est la plus utilisée bien qu’elle ne garantisse pas en général une solution de contrôle optimale. Pour pallier ce problème, nous avons développé une méthode complètement structurelle, sans construction du graphe de marquage, pour les RdPS ordinaires ou généralisés. Elle consiste à déterminer de manière structurelle les contraintes admissibles pour la méthode des invariants. Elle est basée sur la condition de contrôlabilité structurelle des états du RdPS du SED en boucle fermée, obtenu par produit synchrone des RdPS du procédé et de la spécification. En outre, nous avons prouvé que la condition de contrôlabilité structurelle, définie par la condition de marquage des places d’entrée d’une transition synchrone incontrôlable, est équivalente à la condition de contrôlabilité définie par les langages du RdPS. Cette condition définit l’équation d’un hyperplan séparateur qui assure la séparation des états admissibles des états interdits dans le SED. Les contraintes dérivées de d’hyperplan séparateur sont admissibles et peuvent être simplifiées systématiquement. Elles permettent de faire un lien biunivoque entre la théorie de commande par supervision de Ramadge et Wonham et la méthode des invariants pour le calcul d’un contrôleur optimal au sent maximal permissif. Même si pour certaines structures très complexes (à grande échelle), la solution maximale permissive ne peut être garantie directement, notre approche a donné le contrôleur optimal dans les études de cas réels considérés.

We consider the problem in which a supervisor or remote pilot provides a real-time linear velocity reference to a multirotor aerial robot, either through a traditional remote control handset, a modern haptic interface, or semi-autonomous guidance control system. In all such cases, the goal is to servo-control the vehicle's velocity to the set point as quickly and as efficiently as possible. The challenge is to achieve this robustly in the presence of unknown wind disturbances and in situations in which the vehicle moves into global position system (GPS) denied environments (indoors, urban canyons, forests) where estimation of the vehicle's velocity is challenging. These situations include unclutterred environments, poor visibility environments caused by poor lighting, and poorly textured visual environments where laser- and vision-based sensors become unreliable. The approach taken is to develop a coupled nonlinear complementary velocity aided attitude filter that provides estimates of both the inertial and body-fixed frame linear velocities, as well as the attitude of a multirotor aerial vehicle, that functions effectively even when only the inertial measurement unit and barometric sensor measurements are available. When full inertial velocity measurements are available (from GPS, Vicon, or a vision system), the filter additionally estimates the external wind speed. In this paper, we formally present the proposed filter along with experimental results and a comparison of the filter to recent results in the literature and in situations in which inertial reference frame velocities are available intermittently. The proposed filter is computationally simple to implement, easy to calibrate and tune, and provides an excellent base level functionality for modern multirotor aerial robotic systems that will be required to function robustly in a variety of environments.

International audience; Embedded systems need to be more and more self-adaptive, in order to better manage their constrained resources, and to better take into account evolutions in their environment and in their computing architecture. They can benefit from Field Programmable Gate Array (FPGA) architectures , which supports Dynamic Partial Reconfiguration (DPR) of the running fonctions, enabling improved performance and power consumption. The reconfigurations need to be decided and controlled in a closed loop. We approach this problem by applying techniques from the area of Supervisory Control for Discrete Event Systems (DES), where the space of configurations at the different levels (application, tasks, hardware platform) are modeled with automata, using the tools Heptagon/BZR and ReaX. This paper contributes with (i) generic modeling of the behaviors and objectives ; (ii) applications of Discrete Controller Synthesis (DCS), especially logico-numerical control ; (iii) concrete implementation on a FPGA hardware platform for an embedded video processing case study.

International audience; We put forward a new modeling technique for Dynamic Resource Management (DRM) based on discrete events control for symbolic logico-numerical systems, especially Discrete Controller Synthesis (DCS). The resulting models involve state and input variables defined on an infinite domain (Integers), thereby no exact DCS algorithm exists for safety control. We thus formally define the notion of limited lookahead, and associated best-effort control objectives targeting safety and optimization on a sliding window for a number of steps ahead. We give symbolic algorithms, illustrate our approach on an example model for DRM, and report on performance results based on an implementation in our tool ReaX.

TRA 2018, 7th Transport Research Arena, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; Especially in inter-country areas, Crisis Management (CM) faces several challenges. Thorough preparation and anticipation are crucial organizational tools to address those challenges and enable proper reaction to crises. CM requires the joint effort of various stakeholders from different countries: public authorities, private companies, Non-Governmental Organizations (NGOs), etc. need to collaborate under specific, locally different regulations. The present paper includes a brief introduction to the state of the art of CM of international railways with special regard to the topics partnerships, leadership & communication as well as training. As part of a research project, a survey with international crisis management experts was conducted. Based on the survey results, a handbook containing transnational recommendations regarding the involved stakeholders and their responsibilities is developed. Of course, existing CM concepts of relevant organizations are taken into consideration for the development. The handbook was discussed with end-users in the course of a project workshop. In addition, when the crisis management is required, the response is coordinated within the framework of the National Crisis Management System (NCMS). The cooperation between these NCMSs leads to the concept of System-of-Systems (SoS). Based on Supervision Control Theory (SCT), we propose a formal model built from decomposition of NCMSs using a multi-model approach. The resulted framework offers a global view of the SoS and resolves problems of system's dependence and of operating mode management. The proposed model is designed by using the High Level Petri Nets (HLPNs) formalism and is illustrated with a crisis of a railway system. The main result of this paper is the comprehensive knowledge of current crisis management strategies in the context of cross-border incidents. Weaknesses in the existing system are identified and two approaches that seek to enhance CM are introduced.

The design of an active Fault Tolerant Control (FTC) strategy based on Virtual Actuators (VA) and switching control theory is addressed. More precisely, a bank of VA is introduced between the baseline controller and the plant to hide and accommodate the fault. If the proposed solution possesses the advantage to maintain the baseline - and potentially certified - controller, it is also assumed here to keep the analytical diagnosis filters - potentially certified too - that monitor the plant. The problem is next formulated in the context of supervisory control where the cases of intermittent and abrupt faults can be covered. It is shown how a separation principle can be found to guarantee the closed loop stability of the overall switching system by using dwell-time conditions. Finally, the proposed solution is applied to the HiMAT benchmark.

The building sector is considered a major consumer of energy among all economic sectors. It represents approximately 40 percent of energy consumption. An important energy consumer is associated with building heating systems. The main objective of this paper is to use a novel supervisory control strategy based on RBF neural networks architecture to achieve a good temperature regulation in a building zone and to insure operational safety in the presence of different types of disturbances such as neighborhood temperatures, weather data. The simulation results for different situations show the importance and the effectiveness of this control methodology for unknown nonlinear dynamical processes.

International audience; The supervisory control theory is widely used to deal with problems of controller design in the field of discrete event systems. Despite the academic attention over last several decades, there were few application cases in real industrial systems. Some scientific results have shown the difficulties of implementation of Supervisory Control Theory (SCT) and proposed some possible solutions. On the other hand, the difficulty of using the theory for system engineers should also be taken into consideration. This paper presents a modeling approach of SCT based on SysML. Aimed at typical manufacturing systems, a three-level model template is proposed to bridge the gap between SCT and system design. For each template in the modeling library, there is one equivalent model in three levels: the SCT model level, the interface model level and SCT model level. The construction of modeling template is based on the prototype abstraction of typical manufacturing system elements. The transformation algorithms between each model level are given in the paper. The engineer can design the system by the standardized templates and modeling procedures in system engineering level. The correspondent SCT model will be created according to the transformation algorithm and computed the solution automatically. An example will be posed to validate the modeling methodology application at the end of the paper.

Cette Thèse d’Habilitation à Diriger des Recherches (HDR) est effectuée dans le cadre de l’Automatique en général. Elle comporte trois parties distinctes. La première partie concerne la commande des systèmes hybrides et systèmes à commutations (switched systems). La deuxième partie est consacrée à la commande supervisée (supervisory control) des systèmes à événements discrets (discrete-event systems). Enfin les perspectives de recherche sont données dans la troisième et dernière partie.La commande des systèmes hybrides et à commutations traite de la modélisation MLD (Mixed Logical Dynamical Systems) introduite par A. Bemporad et M. Morari (1999).Les systèmes à commutations étant décrits naturellement par un modèle PWA (piecewise affine, affine par morceaux), l’approche MLD est une modélisation alternative. Nous proposons des algorithmes de conversion de PWA vers MLD et vice-versa qui donnent des meilleurs résultats, notamment en temps de simulation.La stabilité d’un système non linéaire à commutations est étudiée en utilisant une approche polynomiale, qui permet de reformuler le système initial en un système continu polynomial, permettant ainsi de prouver sa stabilité Enfin la commande optimale est appliquée aux deux types de systèmes commutés : le cas linéaire et celui non linéaire sont traités par reformulation du système en système polynomial continu, permettant d’utiliser la théorie des moments, qui rend les problèmes de commande optimale plus faciles à résoudre.La deuxième partie concerne les systèmes à événements discrets. Elle a débuté avec la commande supervisée de la cellule flexible de l’EMN, composée d’un convoyeur central et de plusieurs stations robotisées (ISIC 2003, LSS 2004). Ensuite influencé par le thème de recherche des systèmes hybrides et systèmes à commutations (switched systems) venant de l’Automatique continue, nos travaux se sont orientés vers une tentative de définition formelle des SED à commutations (switched DES, MTNS 2006). Toujours dans cette voie, nous avons proposé une définition de systèmes “switched non blocking » (MSR 2013), pour arriver à des systèmes avec plusieurs langages pouvant commuter (switchable languages), suivant le modèle de (Kumar, Takai, Fabian et Ushio, 2005).La troisième et dernière partie est consacrée aux perspectives de recherche. La première perspective concerne la commande optimale de “smart grids”, en exploitant la topologie de commutations (switched topology) dans de tels systèmes. La deuxième perspective traite de la simulation et l’optimisation de systèmes logistiques (le système de tri de bagages Air France à l’Aéroport de Paris-CDG) à l’aide de réseaux de Petri.

Cette Thèse d’Habilitation à Diriger des Recherches (HDR) est effectuée dans le cadre de l’Automatique en général. Elle comporte trois parties distinctes. La première partie concerne la commande des systèmes hybrides et systèmes à commutations (switched systems). La deuxième partie est consacrée à la commande supervisée (supervisory control) des systèmes à événements discrets (discrete-event systems). Enfin les perspectives de recherche sont données dans la troisième et dernière partie.La commande des systèmes hybrides et à commutations traite de la modélisation MLD (Mixed Logical Dynamical Systems) introduite par A. Bemporad et M. Morari (1999).Les systèmes à commutations étant décrits naturellement par un modèle PWA (piecewise affine, affine par morceaux), l’approche MLD est une modélisation alternative. Nous proposons des algorithmes de conversion de PWA vers MLD et vice-versa qui donnent des meilleurs résultats, notamment en temps de simulation.La stabilité d’un système non linéaire à commutations est étudiée en utilisant une approche polynomiale, qui permet de reformuler le système initial en un système continu polynomial, permettant ainsi de prouver sa stabilité Enfin la commande optimale est appliquée aux deux types de systèmes commutés : le cas linéaire et celui non linéaire sont traités par reformulation du système en système polynomial continu, permettant d’utiliser la théorie des moments, qui rend les problèmes de commande optimale plus faciles à résoudre.La deuxième partie concerne les systèmes à événements discrets. Elle a débuté avec la commande supervisée de la cellule flexible de l’EMN, composée d’un convoyeur central et de plusieurs stations robotisées (ISIC 2003, LSS 2004). Ensuite influencé par le thème de recherche des systèmes hybrides et systèmes à commutations (switched systems) venant de l’Automatique continue, nos travaux se sont orientés vers une tentative de définition formelle des SED à commutations (switched DES, MTNS 2006). Toujours dans cette voie, nous avons proposé une définition de systèmes “switched non blocking » (MSR 2013), pour arriver à des systèmes avec plusieurs langages pouvant commuter (switchable languages), suivant le modèle de (Kumar, Takai, Fabian et Ushio, 2005).La troisième et dernière partie est consacrée aux perspectives de recherche. La première perspective concerne la commande optimale de “smart grids”, en exploitant la topologie de commutations (switched topology) dans de tels systèmes. La deuxième perspective traite de la simulation et l’optimisation de systèmes logistiques (le système de tri de bagages Air France à l’Aéroport de Paris-CDG) à l’aide de réseaux de Petri.

International audience; The growth of renewable energy production is changing the future of power transmission systems. In recent years, High-Voltage Direct Current (HVDC) technologies based on Modular Multilevel Converters (MMC) are embraced by industry and academia as a solution for the efficient integration of renewable energies into electrical grids. Faster and more complex control strategies will be needed in this domain which nowadays relies heavily on human decision. This paper proposes a Discrete Event System (DES) approach to manage the control responses to deploy in an HVDC grid. Based on Discrete Event Systems (DES) modelling and Supervisory Control Theory (SCT), this paper proposes a method for synthesizing a supervisory control for HVDC systems, which focuses on local observations and limits the number of events to be communicated. The method is validated by simulation for the start-up of a point-to-point link.

International audience; This paper addresses the design of Petri net (PN) supervisor using the theory of regions for forbidden state problem with a set of general mutual exclusion constraints. In fact, as any method of supervisory control based on reachability graph, the theory of regions suffers from a technical obstacle in control synthesis, which is the necessity of computing the graph at each iteration step. Moreover, based on the reachability graph, which may contain a large number of states, with respect to the structural size of the system, the computation of PN controllers becomes harder and even impossible. The main contribution of this paper, compared to previous works, is the development of a control synthesis method in order to decrease significantly the computation cost of the PN supervisor. Thus, based on PN properties and mathematical concepts, the proposed methodology provides an optimal PN supervisor for bounded Petri nets following the interpretation of the theory of regions. Finally, case studies are solved by CPLEX software to compare our new control policy with previous works which use the theory of regions for control synthesis.

This work proposes a novel structure in Petri nets, namely data inhibitor arcs, and their application to the optimal supervisory control of Petri nets. A data inhibitor arc is an arc from a place to a transition labeled with a set of integers. A transition is disabled by a data inhibitor arc if the number of tokens in the place is in the set of integers labeled on it. Its formal definitions and properties are given. Then, we propose a method to design an optimal Petri net supervisor with data inhibitor arcs to prevent a system from reaching illegal markings with respect to control specifications. Two techniques are developed to reduce the supervisor structure by compressing the number of control places. Finally, a number of examples are used to illustrate the proposed approaches and experimental results show that they can obtain optimal Petri net supervisors for the net models that cannot be optimally controlled by pure net supervisors. A significant result is that the proposed approach can always lead to an optimal supervisor with only one control place for bounded Petri nets on the premise that such a supervisor exists.

International audience; This paper presents a new robust fuzzy control of energy management strategy for the stand-alone hybrid power systems. It consists of two levels named centralized fuzzy supervisory control which generates the power references for each decentralized robust fuzzy control. Hybrid power systems comprises: a photovoltaic panel and wind turbine as renewable sources, a micro turbine generator and a battery storage system. The proposed control strategy is able to satisfy the load requirements based on a fuzzy supervisor controller and manage power flows between the different energy sources and the storage unit by respecting the state of charge and the variation of wind speed and irradiance. Centralized controller is designed based on If-Then fuzzy rules to manage and optimize the hybrid power system production by generating the reference power for photovoltaic panel and wind turbine. Decentralized controller is based on the Takagi-Sugeno fuzzy model and permits us to stabilize each photovoltaic panel and wind turbine in presence of disturbances and parametric uncertainties and to optimize the tracking reference which is given by the centralized controller level. The sufficient conditions stability are formulated in the format of linear matrix inequalities using the Lyapunov stability theory. The effectiveness of the proposed Strategy is finally demonstrated through a SAHPS (stand-alone hybrid power systems) to illustrate the effectiveness of the overall proposed method.

International audience; In this paper, the Discrete Controller Synthesis (DCS) technique is applied in order to obtain a correct-by- construction automatic distributed scheduling of Wireless Sensor Network (WSN). Our approach starts from an abstract formal model considering that communication between nodes are instantaneous. Then, a refined model is obtained by adding a realistic communication mechanism while preserving the global controlled behavior generated initially by automatic synthesis. This communication mechanism is called a synchronization “barrier“: a software mechanism constraining a set of sensors to wait for each other before making its own local decision and before deactivation. The approach is illustrated by a WSN model with two communicating nodes.

The discrete event system (DES) control theory was initially developed usingfinite state automata, with the aim of guaranteeing a priori operation in conformity with thespecifications which are generally decline as forbidden states.The automata represent apowerful modeling formalism of the DESs, despite their great sensitivity to the combinatorialexplosion problem of the number of states. This disadvantage is minimized when the modelingis carried out by the Petri nets (PN). However, this advantage in concision iscounterbalanced by the loss of the optimality of the results provided by the automata.However, among many methods of synthesis of supervisory control by PN, the invariantsmethod is the most used for the However, among many methods of synthesis of supervisorycontrol by PN, the invariants method is the most used for computing the controller.Unfortunately, this approach does not generally guarantee an optimal solution if it is used ina conventional way, and especially in the case where the synchronization of the PNs of theDES is carried out by uncontrollable transitions. The solution consists in identifying theadmissible constraints suitable for the synthesis of the maximum permissive (optimal)controller. We proposed a fusion approach based on the Kumar algorithm to determine theconstraints related to the forbidden boundary states, for computing the controller. But theneed to explore the state space of the PN, namely the marking graph, led us to represent themarking graph by its transition function, namely, the transition matrix. The coding of theelements of the matrix, according to the DES specification enabled us to identify the statesconstituting the hyperplane (decision function) and the appropriate boundary states, La théorie de commande par supervision des systèmes à événements discrets (SED) a été initialement développé à base des automates à états finis (AFD), avec pour objet de garantir à priori un fonctionnement conforme aux spécifications qui se déclinent généralement en états interdits. Les automates représentent un puissant formalisme de modélisation des SED, malgré leur grande sensibilité au problème d’explosion combinatoire du nombre d’états. Cet inconvénient est minimisé lorsque la modélisation est effectuée par les réseaux de Petri (RdP). Cependant, cet avantage en concision est contrebalancé par la perte de l’optimalité des résultats fournis par les automates. Toutefois, parmi de nombreuses méthodes de synthèse de commande par supervision à base RdP la méthode des invariants est la plus utilisée pour le calcul du contrôleur. Malheureusement, cette approche ne garantit pas en général une solution optimale si elle est utilisée de manière classique, et surtout dans le cas où la synchronisation des RdP du SED est réalisée par des transitions incontrôlables. La solution consiste à identifier les contraintes admissibles adéquates à la synthèse du contrôleur maximal permissif (optimal). Nous avons proposé une approche fusionnelle basée sur l’Algorithme de Kumar afin déterminer les contraintes liées aux états interdits frontières, pour le calcul du contrôleur. Mais, la nécessité d’explorer l’espace d’états du RdP , à savoir le graphe de marquage nous a conduit à représenter le graphe de marquage par sa fonction de transition, à savoir, la matrice de transition. La codification des éléments de la matrice, selon la spécification du SED nous a permis d’identifier les états constituants l’hyperplan (fonction de décision) et les états interdits frontières adéquats.

In supervisory control, computational complexity and implementation flexibility represent major challenges when a large number of local components compose a target system. To overcome these difficulties, we propose a formal approach to distributed control synthesis and implementation for automated manufacturing systems (AMS). We assume that the system is modelled with automata in a local modular fashion. Local control specifications are defined for each local subsystem by means of logical equations to construct local controllers (LCs). Then, global control specifications, stated as logical implications, are applied to the LCs, which allows synchronisation and cooperative interaction among the subsystems. This paper makes two contributions. First, it outlines a formal method for constructing minimally restrictive and deadlock-free distributed controllers (DCs). Second, it proposes a method for the interpretation of these DCs into Grafcet, which is a graphical modelling formalism widely used to design the c...

International audience; Supervisory Control and Data Acquisition and Distributed Control Systems named (SCADA/DCS) have played a key role in the design of modern power smart applications, particularly in the automatic management of real time energetic platforms. In this work, we present a semantic cyber security vulnerabilities add to classic one, with the use of semantic embedded application in smart devices in semantic wireless (SCADA/DCS) systems, focusing on the semantic attacks. In this work, we present a new security semantic wireless protocol as a secure communication support for these modern semantic wireless systems named (ZIGBEE/SOAP/SECURITY), obtained by the combination between wireless ZIGBEE protocol, SOAP protocol and the integration of our security mechanism, in the global message header obtained by the fusion between ZIGBEE message and SOAP message.

Current-state opacity is a key security property in discrete event systems. A system is said to be current-state opaque if the intruder, who only has partial observations on the system's evolution, is never able to infer that the current state of the system is within a set of secret states. In this work, we address the problem of enforcing current-state opacity by supervisory control. Given a system that is modeled with a finite automaton and that is not current-state opaque with respect to a given secret, the enforcement problem consists in designing a supervisor so that the controlled system is current-state opaque. We assume that the supervisor can only observe and control a subset of events. To be more general, we assume no specific containment relationship exists between the sets of events that can be observed by the intruder and the supervisor, respectively. We call this general setting uncomparable observations. We show that the maximally permissive supervisor always exists and propose a novel approach for its design.

Supervisory Control Theory (SCT) is an important framework for establishing formal control of discrete event systems (DES). It is divided into two main approaches: (i) the qualitative approach which studies the DES logical performances with respect to the logical states and events; and (ii) the quantitative approach which is interested in the performance assessment, and introduces “Time” to the untimed DES. This work concerns DES where the elapse of time among the events can affect the system behavior. We recently proposed an untimed approach to distributed supervisory control design and implementation. In this paper, the concept of time observer is introduced to incorporate time dependencies to the proposed approach. The applicability of the proposed method is validated by an experimental Automated Manufacturing System (AMS).

The development of microgrids could facilitate the smart grid feasibility that is conceived to improve instantaneous grid power balancing and demand response. It requires microgrid control functions as power balancing, optimization, prediction, and smart grid and end-user interaction. The difficulty is to offer resistance to optimization uncertainties in real-time power balancing. On the basis of direct current (DC) microgrid power system modeling, this chapter presents the supervisory design with predicted power flow optimization for a DC microgrid. The supervisory control, designed as a four-layer structure, takes into account the forecast of power production and load power demand, storage capability, grid power limitations, and grid time-of-use tariffs; optimizes energy cost; and handles instantaneous power balancing in the microgrid. Optimization aims to reduce the microgrid energy cost while meeting all constraints and is performed by mixed integer linear programming. This is an optimization under constraints seen such as offset between prediction uncertainties and planning on the one hand and operational reality and utility grid requirements on the other hand. The real-time operation layer is developed to control the DC microgrid power balance taking into account the considered constraints. Simulation results validate the feasibility of DC microgrid supervisory design and show that the proposed control is able to implement optimization in real-time power balancing with resistance to uncertainties. The designed supervisory control can be a solution concerning the communication between loads and the smart grid.

International audience; This paper deals with the on-line design of a supervisor to coordinate an automated guided vehicle (AGV) fleet. This supervisor ensures the system safety (no collision) and a good coordination between vehicles (no blocking situations). It is the so-called Wonham-Ramadge supervisor, it is the least restrictive, and ensures controllability and nonblocking. We propose a compositional procedure to resolve this problem allowing an efficient on-line synthesis. A calculation on the fly is made at every attribution of a new mission for an AGV, to actualize the supervisor and adapt it to the new situation. This compositional approach allows to increase the number of AGV taken on compared to the monolithic approach. We show on some tests the efficiency of this method for the on-line synthesis of supervisor to coordinate a fleet of mobile robots for real cases.

The theory of regions has been recognized as a powerful method of control synthesis for obtaining maximally permissive and non-blocking controller. Although, the Petri net controller does not always exist, and in some cases, using the theory of regions becomes arduous when the reachability graph is sizable. We aimed in a previous work to reduce the resolution complexity of this theory by synthesizing minimal cuts that represent minimal zone in the reachability graph. In this work, we propose to design Petri net controller by dispossessing the reachability graph. To do so, we synthesize a set of canonic markings on which the theory of regions is applied to calculate the corresponding Petri net controller. Additionally, the Petri net supervisor will recognize and prohibit all event separation instances in order to ensure the maximal permissive behavior. To illustrate the presented policy, an application is implemented on the Flexible Manufacturing System (FMS) at the ENIM (National School of Engineering ofMetz), in FRANCE.

International audience; The problem of avoiding obstacles while navigating within an environment for a Unicycle-like Wheeled Mobile Robot (WMR) is of prime importance in robotics; the aim of this work is to solve such a problem proposing a perturbed version of the standard kinematic model able to compensate for the neglected dynamics of the robot. The disturbances are considered additive on the inputs and the solution is based on the supervisory control framework, finite-time stability and a robust multi-output regulation. The effectiveness of the solution is proved, supported by experiments and finally compared with the Dynamic Window Approach (DWA) to show how the proposed method can perform better than standard methods.

This dissertation work addresses the obstacle avoidance for wheeled mobile robots. The supervisory control framework coupled with the output regulation technique allowed to solve the obstacle avoidance problem and to formally prove the existence of an effective solution: two outputs for two objectives, reaching the goal and avoiding the obstacles. To have fast, reliable and robust results the designed control laws are finite-time, a particular class very appropriate to the purpose. The novelty of the approach lies in the easiness of the geometric approach to avoid the obstacle and on the formal proof provided under some assumptions. The solution have been thus extended to control a leader follower formation which, sustained from the previous result, uses two outputs but three controls to nail the problem. The Leader role is redesigned to be the reference of the group and not just the most advanced agent, moreover it has a active role slowing down the formation in case of collision avoidance manoeuvre for some robots. The proposed method, formally proven, makes the group move together and allow each agent to avoid obstacles or collision in a decentralized way. In addition, a further contribution of this dissertation, it is represented by a modification of the well known potential field method to avoid one of the common drawback of the method: the appearance of local minima. Control theory tools helps again to propose a solution that can be formally proven: the application of the definition of Input-to-State Stability (ISS) for decomposable sets allows to treat separate obstacles adding a perturbation which is able to move the trajectory away from a critic point; Ce travail traite de l'évitement d'obstacles pour les robots mobiles à roues. D’abord, deux solutions sont proposées dans le cas d’un seul robot autonome. La première est une amélioration de la technique des champs de potentiel afin de contraster l’apparition de minima locaux. Le résultat se base sur l’application de la définition de l’ «Input-to-State Stability» pour des ensembles décomposables. Chaque fois que le robot mobile approche un minimum local l’introduction d’un contrôle dédié lui permet de l’éviter et de terminer la tâche. La deuxième solution se base sur l’utilisation de la technique du «Supervisory Control» qui permet de diviser la tâche principale en deux sous tâches : un algorithme de supervision gère deux signaux de commande, le premier en charge de faire atteindre la destination, le deuxième d’éviter les obstacles. Les deux signaux de commande permettent de compléter la mission en temps fini en assurant la robustesse par rapport aux perturbations représentant certaines dynamiques négligées. Les deux solutions ont été mises en service sur un robot mobile «Turtlebot 2». Pour contrôler une formation de type leader-follower qui puisse éviter collisions et obstacles, une modification de l’algorithme de supervision précédent a été proposée ; elle divise la tâche principale en trois sous-problèmes gérés par trois lois de commande. Le rôle du leader est adapté pour être la référence du groupe avec un rôle actif : ralentir la formation en cas de manœuvre d'évitement pour certains robots. La méthode proposée permet au groupe de se déplacer et à chaque agent d’éviter les obstacles, ou les collisions, de manière décentralisée

This dissertation work addresses the obstacle avoidance for wheeled mobile robots. The supervisory control framework coupled with the output regulation technique allowed to solve the obstacle avoidance problem and to formally prove the existence of an effective solution: two outputs for two objectives, reaching the goal and avoiding the obstacles. To have fast, reliable and robust results the designed control laws are finite-time, a particular class very appropriate to the purpose. The novelty of the approach lies in the easiness of the geometric approach to avoid the obstacle and on the formal proof provided under some assumptions. The solution have been thus extended to control a leader follower formation which, sustained from the previous result, uses two outputs but three controls to nail the problem. The Leader role is redesigned to be the reference of the group and not just the most advanced agent, moreover it has a active role slowing down the formation in case of collision avoidance manoeuvre for some robots. The proposed method, formally proven, makes the group move together and allow each agent to avoid obstacles or collision in a decentralized way. In addition, a further contribution of this dissertation, it is represented by a modification of the well known potential field method to avoid one of the common drawback of the method: the appearance of local minima. Control theory tools helps again to propose a solution that can be formally proven: the application of the definition of Input-to-State Stability (ISS) for decomposable sets allows to treat separate obstacles adding a perturbation which is able to move the trajectory away from a critic point; Ce travail traite de l'évitement d'obstacles pour les robots mobiles à roues. D’abord, deux solutions sont proposées dans le cas d’un seul robot autonome. La première est une amélioration de la technique des champs de potentiel afin de contraster l’apparition de minima locaux. Le résultat se base sur l’application de la définition de l’ «Input-to-State Stability» pour des ensembles décomposables. Chaque fois que le robot mobile approche un minimum local l’introduction d’un contrôle dédié lui permet de l’éviter et de terminer la tâche. La deuxième solution se base sur l’utilisation de la technique du «Supervisory Control» qui permet de diviser la tâche principale en deux sous tâches : un algorithme de supervision gère deux signaux de commande, le premier en charge de faire atteindre la destination, le deuxième d’éviter les obstacles. Les deux signaux de commande permettent de compléter la mission en temps fini en assurant la robustesse par rapport aux perturbations représentant certaines dynamiques négligées. Les deux solutions ont été mises en service sur un robot mobile «Turtlebot 2». Pour contrôler une formation de type leader-follower qui puisse éviter collisions et obstacles, une modification de l’algorithme de supervision précédent a été proposée ; elle divise la tâche principale en trois sous-problèmes gérés par trois lois de commande. Le rôle du leader est adapté pour être la référence du groupe avec un rôle actif : ralentir la formation en cas de manœuvre d'évitement pour certains robots. La méthode proposée permet au groupe de se déplacer et à chaque agent d’éviter les obstacles, ou les collisions, de manière décentralisée

International audience; The energy management strategy (EMS) of a Hybrid electric vehicle (HEV) is a supervisory control meant to steer power flows among the different energy sources of the powertrain. The EMS is designed for the purpose of reaching the maximum potential of a given powertrain architecture. Fuel consumption is not the only criterion to be considered for evaluating the global performance of an EMS, as the EMS also impacts other features such as drivability, through engine starts/stops and gear shifts. This paper proposes a general approach to include drivability constraints in the EMS of powertrains provided with discrete automated transmissions. As a first step, determinist dynamic programming (DDP) is used to compute the optimal solution of the resulting optimization problem. This optimal solution is then used to assess the performance of the proposed on-line strategy which is based on the Equivalent Consumption Minimization Strategy (ECMS). Finally, simulation results are completed by a discussion of experimental results, as the proposed on-line strategy has been implemented in a prototype vehicle designed at Renault and tested on a dynamometric bench.

International audience; The security of Supervisory Control and Data Acquistition systems (SCADA) has become these last years, a major worldwide concern. Indeed, several incidents and cyber-attacks stressed the emergency to make more efforts to secure these systems which manage important economical infrastructures. The increasing use of wireless sensors also brings their security vulnerabilities. Therefore, several communication protocols were developed to meet real time and security requirements needed by this kind of systems. WirelessHART is the first approved international standard for industrial wireless devices. It implements several mechanisms to ensure hop-by-hop and end-to-end security. However, despite these mechanisms, it remains possible for an attacker to conduct an attack against such wireless networks. In this paper, we give the first description of a Sybil attack specially tailored to target WirelessHART based SCADA systems. This attack can lead to harmful consequences such as disturbing the infrastructure functioning, interrupting it or more again causing its destruction (overheating of a nuclear reactor).

International audience; In this paper, supervisory control of (max,+) automata is studied. The synthesis of maximally permissive and just-in-time supervisor, as well as the synthesis of minimally permissive and just-after-time supervisor, are proposed. Results are also specialised to non-decreasing solutions, because only such supervisors can be realised in practice. The inherent issue of rationality raised recently is discussed. An illustration of concepts and results is presented through an example of a flexible manufacturing system.

Reachability graph analysis is an important technique for deadlockcontrol, which always suffers from a state explosion problem since it requires togenerate all or a part of reachable markings.Based on this technique, an optimal or suboptimal supervisor with high behavioralpermissiveness can always be achieved. This thesis focuses on designing liveness enforcing Petri net supervisors for FMSs by considering their behavioralpermissiveness, supervisory structure, and computationnal complexity.The following research contributions are made in this thesis.1. The design of a maximally permissive liveness-enforcing supervisor for an FMSis proposed by solving integer linear programming problems (ILPPs).2. Structural complexity is also an important issue for a maximally permissivePetri net supervisor. A deadlock prevention policy for FMSs is proposed, which canobtain a maximally permissive liveness-enforcing Petri net supervisor while thenumber of control places is compressed.3. In order to overcome the computational complexity problem in MCPP and ensurethat the controlled system is maximally permissive with a simple structure, wedevelop an iterative deadlock prevention policy and a modified version.4. We consider the hardware and software costs in the stage of controlimplementation of a deadlock prevention policy, aiming to obtain a maximallypermissive Petri net supervisor with the lowest implementation cost. A supervisorconsists of a set of control places and the arcs connecting control places totransitions. We assign an implementation cost for each control place and controland observation costs for each transition. Based on reachability graph analysis,maximal permissiveness can be achieved by designing place invariants that prohibitall FBMs but no legal markings.5. Self-loops are used to design maximally permissive supervisors. A self-loop ina Petri net cannot be mathematically represented by its incidence matrix. Wepresent a mathematical method to design a maximally permissive Petri netsupervisor that is expressed by a set of control places with self-loops. A controlplace with a self-loop can be represented by a constraint and a selfloopassociated with a transition whose firing may lead to an illegal marking., Notre thèse est consacrée à l’étude de la supervision des réseaux de Petri en vue de la conception de systèmes manufacturiers flexibles. L’objectif est la définition de stratégies de pilotage en ligne pour l’évitement de conflits et d’interblocages, dans le cadre de la théorie de la supervision. Le point de départ de notre travail est d’exploiterle graphe de marquage du réseau de Petri, ce qui permet en particulier d’obtenir des stratégies de commande maximalement permissive pour des problèmes d’évitement de conflits et d’interblocages. Nous avons ainsi introduit des techniques originales, manipulations d’inégalités ou réductions d’ensembles de marquages, destinées à diminuerla complexité algorithmique d’une telle méthode. Dans premier temps, nous avons focalisé sur la synthèse de superviseurs dits purs, ce qui correspond au cas particulier où l’ensemble de marquage légaux, est convexe.Cette optimisation est ensuite considérée du point de vue de la facilité de mise en oeuvre. Nous traitons ainsi de la minimisation de la structure du superviseur et de son coût d’implémentation en préservant une structure de supervision qui offre à la fois la permissivité maximale et une complexité de calcul raisonnable en vue d’utilisationsur des installations réelles. Aussi, nous avons cherché à réduire le nombre de places de contrôle nécessaires pour réaliser un superviseur maximalement permissif, pour cela nous avons formule le calcul du nombre minimal de places de contrôle en termes d’un problème de programmation linéaire. Afin d’affaiblir la complexité de ce calcul de superviseur, deux versions de l’algorithme sont proposées. Ce problème de minimisation de la taille dusuperviseur, quoique fondamental, n’est pas abordé aussi directement dans la littérature. Il s’agit là d’une première contribution.Dans u second temps, nous nous sommes intéressés aux réseaux de Petri à boucles (self-loops). Les boucles étant représentées par une variable qui s’ajoute dans la contrainte inégalité définissant l’ensemble de marquages légaux. Après avoir proposé une méthode de réduction du nombre d’inégalités ainsi que du superviseur optimalen se basant sur les approches et résultats précédents, nous avons établi une condition suffisante d’obtention d’un superviseur maximalement permissif permettant de traiter des ensembles de marquages légaux non convexes.Enfin nous proposons une méthode de synthèse de contrôleur pour une nouvelle classe de réseaux de Petri, avec des arcs inhibiteurs correspondant à des contraintes définies par des intervalles. La taille du contrôleur ainsi obtenu et défini en termes d’arcs inhibiteurs à intervalles s’en trouve réduite ainsi que par conséquent sont coût d’implémentation.

This paper deals with supervisory control synthesis of Petri net controller for forbidden state transition problem based on a new utilization of the theory of regions. Two different approaches are proposed to reduce the resolution complexity of the theory of regions by minimizing the total number of equations in its linear system. These two approaches are based on a new concept of minimal cuts in reachability graph. The supervisor is a Petri net controller for each minimal cut. Moving from one control place to another allows the switch of minimal cuts in the reachability graph. These new approaches allows also to determine a Petri net controller when it doesn't exist using the classical approach of the theory of regions. To illustrate the present methods an application is implemented on the Flexible Manufacturing System (FMS) at the ENIM (National school of engineering of Metz) in FRANCE.

International audience; The problem of air-fuel ratio stabilization in spark ignition engines is addressed in this paper. The proposed strategy consists of proper switching among two control laws to improve quality of the closed-loop system. The first control law is based on an a priori off-line identified engine model and ensures robust and reliable stabilization of the system at large, while the second control law is adaptive, it provides on-line adaptive adjustment to the current fluctuations and improves accuracy of the closed-loop system. The supervisor realizes a switching rule between these control laws providing better performance of regulation. Results of implementation on two vehicles are reported and discussed.

International audience; Model Predictive Control (MPC) has been widely used and proved efficient in the control ofbuilding installations. It is particularly efficient in the supervisory control of equipment sinceit can integrate economic, social and environmental dimensions in the computation of thecontrol input. In practice, these equipment possess their own devoted and integrated controllers,which include power saturations and operating modes. Therefore, equipment's inputs cannot bedirectly controlled by supervisory controllers. This paper aims at analysing to what extent MPCcontrollers can incorporate existing integrated controllers without introducing extra complexityto their strategies. A Proportional-Integral (PI) controller, with an anti-windup mechanism, hasbeen implemented as the so-called integrated controller. A proposed MPC strategy is discussed.Despite the hybrid functioning of the PI controller, it maintains the simplicity of the problemsolving. Furthermore, a comparison between the performances of a benchmark MPC controller(which would drive directly an equipment possessing no integrated controller) and the developedMPC controller is presented. For this study, an office building is targeted and the heating issuehas been addressed.

International audience; One of the biggest challenges to drill deeper tunnels in the future is to design new maintenance tools. Advanced teleoperation and supervisory control techniques were identified in the Telemach project as potential solutions to carry out this work. Due to limitations of the existing systems, a complete framework merging virtual reality tools and real equipment was designed. A wide range of assistances were developed to reduce the impact of secondary tasks during the maintenance process, offer helpful guiding capability and secure the task execution according to the context. The feasibility of the principle was demonstrated on key operations on a scale one mock-up of a Tunnel Boring Machine section. Attention was paid to develop generic tools, meaning that the whole high-tech construction industry could benefit from these new technologies. (C) 2014 Elsevier B.V. All rights reserved.

This paper presents a photovoltaic-storage-microturbine based DC microgrid, with multi-layer supervision which optimizes efficiently operation while satisfying constraints. Based on forecast data and using a mixed integer linear programming optimization, a predictive power flow is obtained which leads to an optimization-based strategy for real-time power balancing. Experimental test proves the feasibility of the supervisory control and demonstrates the problem formulation of minimizing total energy cost.

In this work, we present a semantic cyber security system and we study its semantic intelligent systems vulnerabilities, focusing on the semantic attacks. For resolving semantic problems we propose a security global solution for the new generation of SCADA systems. The proposed solution aims at protecting critical semantic SCADA processes from the effects of major failures and semantic vulnerabilities in the modern IT-SCADA network. We used a security block in the global network access point, security protocols deployed in different network (OSI) levels and security ontologies deployed in security devices. We used our mixed coordinates (ECC) cryptography solution, this is an encryption technology developed specifically for low latency embedded applications. We integrated security mechanisms in specific SCADA protocols as Modbus. Moreover, we made use of the WS-Security framework and we crypt and signed all the improved security protocols frames with our mixed (ECC) and a hash function.