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International audience; In the beginning of 2022, the world is still fighting the crisis caused by the COVID-19 outbreak. The scientific community is still dedicating significant efforts to identify which are the better strategies to mitigate the pandemic and establish how and when to apply them. Modeling and simulation are a common method to replicate and foresee the behavior of the epidemic curve, but traditional analytical models are not capable to explain and reproduce the real evolution of the number of infections and deaths as they only concentrate in the epidemiological aspects of the virus. The COVID-19 crisis has an impact in all fundamental levels of society, and this is the reason why its modeling requires a global perspective and a holistic approach. Though the engineering scope is not common in the study of public health crises, this paper concludes that some engineering tools such as systems analysis and control theory may be the answer to build a high-fidelity model to support the decision-making facing the emergency.

Over the past two decades, the promoters of Model Based Systems Engineering (MBSE) have encouraged systems engineers to transition from document-centric approaches to model-based ones. Literacy of systems engineers in reading, sharing and elaborating models has therefore become an issue. Whatever the modeling language, elaboration of models is a highly complex intellectual process and SysML is no exception. Feedback from industry practitioners and MBSE lecturers suggests that developers of SysML models often stumble on the same problem: thinking about the system before modeling it in SysML. The authors of this paper propose to ease that elaboration process by using mind maps. With their graphic form and rather flexible way of organizing ideas, mind maps turn out to be a good candidate to help thinking about the system. Unlike approaches that directly switch from mind maps to SysML diagrams dedicated to one specific system, this paper introduces an intermediate step: mind maps first enable elaboration of diagrams patterns. The latter may in turn be instantiated onto one or several systems. Without loss of generality, the proposed approach is step-wise illustrated on real-time systems monitored by software controllers. Patterns are proposed to cover need expression, requirement capture, use case driven analysis and design.

A prominent pathway for the aeronautical industry to meet contemporary challenges is to explore overall vehicular efficiency gains enabled by various functional and structural distributions and/or synergies between onboard systems. To that end, this paper combines analytical first-principle-based methods and principles of systems engineering and focuses on the Environmental Control System (ECS). The objective is to develop means for simple blank-sheet design of complete system architectures, which would help unlock potentially obscured parts of the system design space. Basic thermodynamics is employed, complemented with “Function- Behaviour-Structure-Experience” systems engineering framework. The method presented in the paper enables users to initialise the design from a primitive abstract system architecture described by elementary physical processes, and then carry out a sequence of decisions and design material systems architecture, i.e. concepts that respond to the system requirements. The preliminary results present development of architectures representative both of traditional pneumatic and innovative electrical ECS concepts. Energy consumption figures of merit (thermodynamic efficiency, exergy destruction rate) are used as guidelines during the design i.e. for a given flight condition, the designer can assess the influence of each choice on the overall system energy consumption. Trade-offs between architectural design choices and figures of merit are thus rendered transparent in preliminary architecture design. In this paper the figures of merit are based on thermodynamic energy efficiency; in perspectives the method can include other constraints such as e.g. weight, volume, cost, or other, with long-term objective of enabling a comprehensive multi-disciplinary multi-system aeroplane architecture design scheme.

This paper proposes a novel model-based approach to technology planning and roadmapping, consisting of two complementary steps: technology forecasting and game-theoretic planning. The inherent uncertainty of target technology performances, timelines and risks impact the roadmapping process. Reducing this uncertainty is a major challenge and allows elaborating different options and scenarios. A formal methodology is proposed for quantitative forecasting in a multi-dimensional space (different performance metrics and time) based on past technology development trend information. The method adopts concepts and approaches from econometrics and is formulated as a convex optimization problem with different constraints on the frontier’s shape. It provides useful product line assessment benchmarks and helps to set reasonable goals for future technology developments. Game-theoretic planning allows addressing the strategic decisions to take, considering the technology land-scape, markets, and competition. The strategic decisions affect in turn other companies as well, which is the basis for the application of game theory, in the form of best-response functions to determine the subsequent reactions and movements of rivals in a technological landscape. The result is a simulation of a sequential game in tech-nology space, allowing evaluating possible technological development pathways and determining optimal models on the Pareto frontiers, potential targets for technology roadmapping.

Rapport benchmark formations ingénierie systèmes.

The widespread of Unmanned Aerial Vehicles (UAVs) in various application domains has questioned the design methods used by UAV manufacturers. Migration from document centric approaches to Model-Based ones has stimulated research work on modeling languages and tools that reduce cost development and time to market. Among the various benefits one may expect from using a Model-Based System Engineering approach, the paper essentially considers a model as a reference for early detection of design errors in the life cycle of UAVs. The paper proposes designers to model the UAV in SysML and to use the free software TTool for safety analysis. TTool includes a SysML model editor, a model simulator and formal verification modules that rely safety analysis on mathematics rather than chance. The method associated with SysML and TTool is applied to a UAV in charge of taking pictures.

International audience; In recent years, data visualization has received a lot of attention and widely applicate in many areas. Data is a treasure, a lot of valuable information hidden inside. While visualizing the hidden information concisely and intuitively is a critical task. In this paper, we explore how data visualization could support conceptual design. A specific conceptual design case for improving the fuel efficiency of wheel loader is implemented. By visualizing the complex fuel consumption data comprehensive for engineers to get insights, thus to support the decision making for a new product development. As a result, a table of classifying visual techniques by different features, and a prototype consisted of four approaches step by step to present complex data are proposed.

International audience; Operating a modern technical system, such as a train or aircraft, calls for good organised engineering, operation and maintenance to keep the system in an optimal operational condition. Predictive maintenance is being studied and has as aim to identify errors early enough to still be able to propose a suitable solution before a real incident occurs. After all, technical problems in service may lead to delays or even interruptions of service due to extensive repair actions, such as the replacement of components. Often, predictive maintenance aims at recognising patterns in time series of monitored data and classifying these patterns as known conditions (faulty or correct). As such it provides a vital source of information for maintaining a healthy operational status. However, these approaches are still in their early phases and rely still heavily on skill and experience from the expert. In this paper, the use of self-organising maps for predictive maintenance is being discussed, applied to data of a jet engine. The aim of the study was to assess the usability of such approaches to real-life situations, assessing the learning and validation phases.

The aeronautics sector is currently living an unprecedented growth largely due to innovative projects. In several cases, such innovative developments are being carried out by Small and Medium sized-Enterprises (SMEs). For instance, in Europe, a handful of SMEs are leading projects like airships, large civil drones, or flying cars. These SMEs have all limited resources, must make strategic decisions, take considerable financial risks and in the same time must take into account the constraints of safety, cost, time and performance as any commercial organization in this industry. Moreover, today, no international regulations fully exist for the development and certification of this kind of projects. The absence of such a precise and sufficiently detailed regulatory framework requires a very close contact with regulatory instances. But, SMEs do not always have sufficient resources and internal knowledge to handle this complexity and to discuss these issues. This poses additional challenges for those SMEs that have system integration responsibilities and that must provide all the necessary means of compliance to demonstrate their ability to design, produce, and operate airships with the expected level of safety and reliability. The final objective of our research is thus to provide a methodological framework supporting SMEs in their development taking into account recent innovation and institutional rules of the sector. We aim to provide a contribution to the problematic by developing a specific Model-Based Systems Engineering (MBSE) approach. Airspace regulation, aeronautics standards and international norms on systems engineering are taken on board to be formalized in a set of models. This paper presents the on-going research project combining Systems Engineering and Project Management process modeling and taking into account the metamodeling problematic.

International audience; The paper shares an experience in using SysML and the free, open-source software TTool for protocol modelling and communication architecture validation. A dialogue between a pilot and a control tower serves as running example to demonstrate the benefits of complementary model analysis techniques: simulation, model checking, and verification by abstraction. The proposed method may be adapted to other modelling languages and tools.

Le secteur aéronautique voit actuellement arriver de nouveaux types d'entrants, des systémiers innovants, en majorité des Petites et Moyennes Entreprises (PME), souhaitant développer et commercialiser de nouveaux moyens de transport. Des projets comme les dirigeables, les drones civils de transports de marchandises, les drones dits « taxi aérien », deviennent ainsi des préoccupations sérieuses pour tous les acteurs du marché où la sécurité des personnes et des infrastructures est un enjeu majeur. Dans ce cadre, le processus de certification, cœur de l'activité aéronautique, demeure une activité critique. Le secteur aéronautique est une industrie très structurée, organisée selon de nombreuses règles, normes et standards qui ne facilitent pas l'arrivée de ces nouveaux acteurs. Les PME concernées requièrent un support méthodologique pour les accompagner dans leurs développements et faire face à la complexité du marché. Nous proposons d'aborder la problématique par une approche d'ingénierie système basée sur les modèles et une modélisation hiérarchisée des processus d'entreprise.

Agile methods are receiving a growing interest from industry and these approaches are nowadays well accepted and deployed in software engineering. However, some issues remain to introduce agility in systems engineering. The objective of this paper is to show an agile management implementation in an educational project consisting in developing a connected mobile robot, and to evaluate the issues and benefits of adopting an agile approach. Among the most famous agile management methods, SCRUM has been chosen to lead this experiment. This paper first presents the project and how students traditionally manage it, then it describes how Scrum could be used instead. It evaluates the difficulties and interests to introduce agility in this project, and concludes on the ability of Scrum to design, test and progressively integrate the system, thus providing an operational prototype more quickly.

“Cyber Physical Systems” (CPS), continuously connected to the rest of the world, communicating autonomously with other systems and with a certain degree of autonomy for taking decisions, pose certain challenges to industries, but to the training of the next generation of engineers as well. The inclusion of different aspects of CPS in the educational programs is important to prepare the students for the development of such systems. The paper aims at looking at the development of CPS, identifying where and how it is important to train the students in particular. The core of the paper is dedicated to multi-paradigm modelling as a key enabler for mastering the complexity of CPS and focuses on educational challenges and relies on the authors’ experience with the SysML tool TTool and the WoPANets tool that implements network calculus theory.

Le présent article traite de la détection d'une combinaison linéaire de signaux mono fréquentiels noyée dans un bruit large bande, dans le cas où leur fréquence n'est connue qu'approximativement. Nous démontrons que les déviations de fréquence provoquent un élargissement du sous-espace signal. Son expression analytique nous permet de construire une base adaptée de ce sous-espace élargi que nous utilisons pour robustifier le test de détection du rapport de vraisemblance généralisé (GLRT). Les performances de la méthode proposée sont illustrées par des résultats numériques.

Procédé de traitement du signal de détection de cliquetis d'un moteur à combustion interne dans lequel le signal utile s(t) est assimilé à une combinaison linéaire de P résonances de type caractérisé en ce qu'afin de tenir compte de la variation de fp autour de fp il comporte les étapes suivantes :. assimilation de à une petite valeur,. approximation du signal utile au moyen d'un développement limité à l'ordre R autour des fréquences nominales fp,. calcul d'un détecteur de cliquetis LR(x),. comparaison de la valeur du détecteur de cliquetis LR(x) avec une valeur seuil gammaR,. détermination de la présence de cliquetis si LR(x) > gammaR

Standard knock sensor signal processing typically consists of band-pass filtering followed by integration over a specified time/angular window. The resulting knock intensity serves as input to knock detection & correction part of an engine management system (ECU). While this treatment was initially performed by dedicated ICs, it has recently been implemented by ECU software, leading to a digital signal processing approach. In spite of some evident advantages of this approach, the processing method itself had not changed significantly. In this paper, the possibilities of taking better advantage of digital signal processing techniques are discussed and investigations on some possibilities for improving the overall knock detection performance by means of enhancing the signal processing techniques are presented.

This paper examines performance of the knock detection technique typically used in engine control systems, and the margin for possible improvement. We introduce a knock signal model and obtain an analytical result for the associated receiver operating characteristic of the standard knock detector. To show the improvement potential, we derive the theoretical upper bound of performance. A special case with unknown model parameters is also considered. Numerical results stimulate the research of improved detectors.

Le marché de l'aviation fait face aujourd'hui à une croissance rapide des technologies innovantes. Les drones cargo, les taxis drones, les dirigeables, les ballons stratosphériques, pour n'en citer que quelques-uns, pourraient faire partie de la prochaine génération de transport aérien. Dans le même temps, les Petites et Moyennes Entreprises (PMEs) s'impliquent de plus en plus dans la conception et le développement de nouvelles formes de système aéroporté, passant du rôle traditionnel de fournisseur à celui de concepteur et intégrateur. Cette situation modifie considérablement la portée de la responsabilité des PMEs. En tant qu'intégrateurs, elles deviennent responsables de la certification des composants et du processus de fabrication, domaine dans lequel elles n’ont encore que peu d'expérience. La certification, qui requiert une connaissance très spécifique des réglementations, des normes et standards, demeure un processus obligatoire et une activité critique pour les entreprises de l'industrie aéronautique. C’est aussi un défi majeur pour les PMEs qui doivent assumer cette responsabilité de certification avec des moyens limités. Dans cette thèse, deux besoins majeurs sont identifiés: le soutien méthodologique n'est pas facilement disponible pour les PMEs; et les exigences de certification ne sont pas facilement compréhensibles et adaptables à chaque situation. Nous examinons donc des voies alternatives pour réduire la complexité de la situation des PMEs. L'objectif est de fournir un soutien afin qu'elles puissent être plus efficaces pour comprendre et intégrer les règles, les législations et les lignes directrices à leurs processus internes de manière plus simple. Cette thèse propose ainsi une approche méthodologique pour soutenir ces organisations. Développée en étroite collaboration avec une PME française, l'approche est composée d'un ensemble de modèles (métamodèle, modèles structurels et comportementaux) couverts par un mécanisme de gouvernance. The aviation market is facing nowadays a fast growth of innovative airborne systems. Drone cargo, drone taxi, airships, stratospheric balloons, to cite a few, could be part of the next generation of air transportation. In the same time, Small and Medium-sized Enterprises (SMEs) are becoming more and more involved in designing and developing new forms of air transportation, transitioning from the traditional role of supplier to those of system designer and integrator. This situation changes drastically the scope of SMEs' responsibility. As integrators they become responsible for certification of the components and the manufacturing process, an area in which they have little experience. Certification mandates very specific knowledge, regarding the regulations, norms and standards. Certification is a mandatory process and a critical activity for the enterprises in the aerospace industry. It constitutes a major challenge for SMEs who have to take on this certification responsibility with only limited resources. In this thesis, two major needs are identified: methodological support is not easily available for SMEs; and certification requirements are not easily comprehensive and adaptable to each situation. We examine alternate paths, reducing the complexity and bringing one step closer to solving the problem for the innovative SMEs. The objective is to provide support so that they can be more efficient to comprehend and integrate rules, legislations and guidelines to their internal processes in a simpler way. This thesis proposes then a methodological approach to support such organisation. Developed in close cooperation with a French SME in this situation, the approach is composed of a set of models (metamodel, structural, and behavioural models) covered by a certification governance mechanism.