Archive ouverte de l'ENAC
Not a member yet
3458 research outputs found
Sort by
Integrating Realistic 3D Aircraft Trajectory Optimization with Climate Impact Metrics for Sustainable Aviation
No full textResilient and Robust Strategies for Swarming Ad-hoc Networks
No full textWe investigate a set of methods aimed at enhancing the resilience and robustness of a mobile communication network, with a focus on a case involving a nanosatellite swarm network. The proposed method focuses ongraph division techniques, aiming to recover from impairments while preserving the primary function or mission of the mobile network. By examining the effects of exploration and random selection algorithms on networkrobustness and resilience, our findings indicate that fair graph division consistently strengthens system robustness by reducing the number of packets to transmit, regardless of the algorithm employed. Additionally, our anal-ysis highlights the superior performance of exploration algorithms, such as MIRW, in enhancing robustness and resilience
FLighthouse: Python Development Framework for Multi-Agent Guidance and Path Planning for Unmanned Aerial Systems
No full textInternational audienceThis paper introduces FLighthouse, an open-source python [1] framework designed for development and testing of multi-agent guidance and path planning algorithms. FLighthouse is composed of three key components: SceneBuilder for intuitive 2D use case creation, guidance algorithms integration, and an execution module with visualization and post processing tools. The proposed framework can be used with a wide range of guidance and path planning algorithms and allows for execution and comparison of metrics for different guidance approaches. The framework supports execution in both simulation and real flights. The visualization tool is equipped with analysis tools for detailed interpretation of results. It can also provide real time feedback for immediate assessment. The effectiveness of the proposed framework is demonstrated with three different example scenarios. Example cases demonstrate comprehensive use of the features and highlight the interoperability and compatibility of the framework. FLighthouse's minimal system requirements, necessitating only Python 3 and a few additional libraries, facilitate installation and ensure compatibility across a broad range of systems, enabling rapid development and testing of novel guidance methods
Non degeneracy of affinelike lie algebra
No full textInternational audienceThe aim of this note is to prove some cohomological vanishing theorems for non solvable affinelike Lie algebras, say ALLA. There are some relevant consequences of our vanishing theorems: (1) Every real non solvable affinelike Lie algebra is formally nondegenerate in the sense of A. Weinstein, (Theorem 1.1). (2) Let G be a non solvable Lie group whose Lie algebra is an affinelike Lie algebra (g,e). If the radical of [ker(ad(e)),ker(ad(e))] is commutative, then G admits a left invariant symplectic structure if and only if it has an open coadjoint orbit, (Theorem 1.2). (a) In Section 6, we use our vanishing theorems to supply an algebraic proof of the normal form theorem for Lie non solvable a-algebroids
Planetary boundaries and regional justice: Rethinking aviation transitions through AESA
No full textInternational audienceDespite growing scrutiny of aviation’s environmental footprint, no study to date has assessed future aviation pathways through the lens of the Planetary Boundaries framework. Our team conducted the first absolute environmental sustainability assessment (AESA) of global civil aviation futures, revealing that even ambitious decarbonization scenarios transgress core planetary boundaries (climate change and biosphere integrity) when assessed against an ethically grounded share of safe operating space.Building on this foundation, the present work extends AESA to the regional scale, addressing the need to consider divergent regional capacities and responsibilities in sustainability transitions. We evaluate region-specific aviation scenarios sourced from institutional, industrial, and academic literature, using prospective life-cycle assessment combined with Integrated Assessment Model projections via the premise package.We integrate key sources of regional differentiation, including electricity mix evolution, biomass availability, and historical contributions to global impacts, and we explore multiple ethical-based allocation principles to operationalize fair regional planetary boundaries budgets.Our results reveal sharp contrasts between regions: some face tighter sustainability constraints due to high historical impacts and limited renewable resources, while others may pursue lower-impact pathways. These differences are masked in global assessments, but essential for designing just and effective transition strategies.This work advances aviation AESA by embedding regional granularity and ethical considerations, offering actionable insights for sustainable aviation futures
Comment repenser les retours vibrotactiles dans les interfaces humain-machine : Utilisation des principes de la Gestalt pour concevoir des messages intelligibles pour des situations critiques
No full textInternational audienceIn safety-critical systems, vibrotactile interfaces may offer a suitable substitute or a complement to visual and auditory channels to convey information to operators. However, the conception of vibrotactile stimuli for such applications often relies on a low-level signal design, focusing on sensation with limited consideration for the overall perceptual organization of the stimulus. This PhD research aims to rethink vibrotactile feedback design through the lens of Gestalt theory, in order to create structured tactile messages that follow Gestalt organizational laws of perception. The central hypothesis supports that Gestalt principles can lead to the design of patterns that are more robust and efficiently processed. To this end, this research seeks to provide Gestalt-grounded design guidelines for vibrotactile stimuli applied to high-demand contexts. These guidelines will support the implementation of vibrotactile interfaces that improve operational performance by redistributing cognitive load across sensory modalities, integrating the tactile channel alongside vision and audition, while maintaining intelligibility of the transmitted message.Dans des environnements critiques, les interfaces vibrotactiles pourraient représenter un substitut ou un complément approprié aux canaux visuels et auditifs pour transmettre des informations aux opérateurs. Cependant, la conception de stimuli vibrotactiles pour de telles applications repose souvent sur un design du signal de bas niveau, se concentrant notamment sur la sensation avecune considération limitée pour l’organisation perceptive globale du stimulus. Cette thèse vise à repenser la conception des retours vibrotactiles à travers le prisme de la Gestalt, afin de créer des messages tactiles structurés qui suivent les lois organisationnelles perceptives de la Gestalt.L’hypothèse centrale soutient que les principes de la Gestalt peuvent conduire à l’élaboration de patterns qui sont traités de manière plus robuste et efficace. Ainsi, cette recherche a pour but de fournir des directives de conception basées sur la Gestalt pour les stimuli vibrotactiles appliqués aux contextes critiques. Ces principes de conception viseront à soutenir l’implémentation d’interfaces vibrotactiles qui améliorent la performance opérationnelle en redistribuant la charge cognitive entre les modalités sensorielles, intégrant la modalité tactile aux côtés de la vision et de l’audition, touten maintenant l’intelligibilité du message transmis
Integrity and Continuity Concepts of a Vision-Integrated Navigation System for a Civil Aircraft During a Precision Approach
No full textInternational audienceThis paper investigates the integration of optical sensors (e.g., monocular or stereo cameras, long-wave infrared or short-wave infrared sensors) into the navigation system of a civil aircraft for precision approach operations. The vision-based measurements are tightly fused with a navigation-grade inertial measurement unit (angular drift on the order of 0.01 degrees/hr), an SBAS-augmented GNSS receiver, and a barometric altimeter. The vision system relies on landmark-based positioning, where visual landmarks are located on the runway. The primary motivation for incorporating vision is to mitigate GNSS losses of service and possible navigation continuity losses caused by radio-frequency interference. While vision enhances continuity, it introduces additional failure modes, which pose integrity challenges under civil aviation standards. A technical challenge arises: vision integration increases the integrity requirements on the GNSS signals. To address this, a dual-navigation architecture is proposed. It operates with an SBAS-augmented inertial-GNSS fusion as long as GNSS is available, and switches to an inertial-vision fusion when GNSS is declared unavailable. The objectives of this paper are: (i) to formally analyze the impact of vision integration in terms of continuity and integrity, (ii) to propose fault allocation trees for the hybrid system, (iii) to assess vision-specific failure modes, and (iv) to derive integrity and continuity requirements for future vision-based integrity monitoring algorithms
GRust: A Programming Language for Automotive Engineering
No full textInternational audienceThe increasing complexity of embedded automotive software necessitates a strong focus on safety. ISO 26262 mandates reliability in critical systems, ensuring secure and bounded memory usage, bounded execution time, and protection against division-by-zero and overflow errors. Automotive software is typically modeled in Simulink and Stateflow, generating ISO 26262-compliant C code under a periodic execution paradigm. However, for data-driven applications such as automated driving, periodic execution leads to redundant computations and bus overloads, requiring manual optimization. To address these issues, we introduce GRust, a domain-specific language for automotive system modeling. GRust generates Rust implementations that enforce compile-time safety properties while optimizing execution through change propagation. Additionally, it integrates a verification wrapper of Creusot for formal property validation. This paper presents the design of GRust, its implementation, and verification capabilities, demonstrating its potential to improve both the reliability and efficiency of automotive software
Navigating the LEO Network: A Routing Optimisation Approach
No full textInternational audienceLow Earth Orbit (LEO) constellations are transforming today’s modern communication era by enabling highspeed, low-latency, and reliable broadband services at a global scale. Despite their huge potential, designing efficient mechanisms for satellite networks is challenging due to the dynamic nature of LEO satellites. In this paper, we focus on routing in LEO constellations including Inter-Satellite Links (ISLs) with several constraints like e.g. minimising the maximum link utilisation. We propose a static approach aiming to find optimal paths to transmit traffic demands in the network graph. We consider Linear Programming (LP) to formulate problems for different network constraints and show that we are able to provide solutions respecting the various constraints, including those related to quality of service (QoS).<br /
Modelling Subjective Complexity through Cognitive Transitions: Extended Framework
No full textInternational audienceMeasuring the operational complexity of arrival traffic is critical for supporting decision-making and enhancing traffic management. In our previous work, we proposed a subjective complexity metric that captures transitions in controllers' workload. However, it has certain limitations, as it does not fully integrate domain-specific knowledge-such as the airspace structure of the terminal maneuvering area-and lacked a systematic approach for defining decision boundaries between complexity levels.This study addresses these limitations through two key enhancements. First, the airspace structure information is incorporated into trajectory analysis, enabling a better characterization of arrival traffic dynamics. Second, a systematic method is developed for automatically determining decision boundaries between complexity levels, thereby reducing reliance on subjective human judgment.Using real-world traffic data, the enhanced metric outperforms the baseline in capturing workload variations associated with additional controller-issued manoeuvres. Besides, the automatic boundary determination produces results comparable to manually defined boundaries while improving measurement consistency. Together, these enhancements provide a more reliable assessment of controller workload.</div