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Increasing Automation on Mission Planning for Heterogeneous Multi-Rotor Drone Fleets in Emergency Response
No full textInternational audienceDrones are increasingly vital for disaster management, yet emergency fleets often consist of heterogeneous platforms, complicating task allocation. Efficient deployment requires rapid assignment based on vehicle and payload characteristics. This work proposes a three-step method composed of fleet analysis, area decomposition and trajectory generation for multi-rotor drone surveillance, aiming to achieve complete area coverage in minimal time while respecting no-fly zones. The three-step method generates optimized trajectories for all drones in less than 2 min, ensuring uniform precision and reduced flight distance compared to state-of-the-art methods, achieving mean distance gains of up to 9.31% with a homogeneous fleet of 10 drones. Additionally, a comparative analysis of area partitioning algorithms reveals that simplifying the geometry of the surveillance region can lead to more effective divisions and less complex trajectories. This simplification results in approximately 8.4% fewer turns, even if it slightly increases the total area to be covered
Microwave sink using plasma-based localized surface plasmons
No full textInternational audienceOvercoming the diffraction limit, meaning focusing waves on a sub-wavelength scale, has received considerable attention for applications involving light and acoustics. Indeed, the intense focusing achieved enhances the interactions between waves and matter, and the improved spatial resolution opens up possibilities in fields such as imaging, detection and communication. In optics, a passive sink may be obtained if the incident light couples to localized surface plasmon (LSP) resonances, resulting in Coherent Perfect Absorption condition. The presence of optical surface plasmons at metal interfaces is due to the angular frequency of metals, which lies in the optical regime due to their high density of free electrons. Plasmas, which consists of ionized gazes with a lower electron density, can support surface plasmons in the microwave regime. Hence, we demonstrate in this paper that sub-wavelength plasmas behave as a passive microwave sink by exciting LSP resonance inside the plasma
A Constraint Programming Approach for Urban Drone Trajectory Optimization
No full textInternational audienceWe address the optimization of drone trajectories in urban environments. We introduce a Constraint Programming formulation for a version of the problem where the vehicles are at the same flight level and their path to fly by is known. We show that, compared to an approach based on a Mixed-integer Linear Optimization model introduced previously, the Constraint Programming approach allows better performances to be achieved in the solution of the problem for a specific instance structure
Improving Incremental Nonlinear Dynamic Inversion Robustness Using Robust Control in Aerial Robotics
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Unlocking Runway Capacity: Enhancing Efficiency through Dynamic Pairwise Aircraft Wake Separation
No full textInternational audienceRunway capacity is one leading bottleneck in nearground flight operations due to various operational constraints, such as aircraft wake separation and runway occupancy time. With rising air travel demand and limited opportunities for infrastructure expansion, enhancing capacity and efficiency has become a critical priority. To address this, both the European Union Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) have introduced aircraft type re-categorization to loosen the distance-based wake separation standards proposed by International Civil Aviation Organization (ICAO). Additionally, dynamic separation, which accounts for weather and aircraft-specific factors, is an emerging focus.Based on our previous studies of aircraft wake vortex decay prediction, two levels of wind-related wake separation matrices are proposed in this paper. Furthermore, two kinds of deep learning models are built to predict aircraft wake separation based on Light Detection And Ranging (LiDAR) data, flight data from Automatic Dependent Surveillance-Broadcast (ADSB) and Meteorological Aerodrome Report (METAR) data. We further build the runway arrival sequencing and scheduling model to explore the potential of runway capacity improvement under proposed dynamic wake separation matrices. Both the theoretical and operational runway capacity at Hong Kong International Airport (HKIA) are investigated using historical arrival flight data. The results indicate that compared to the traditional ICAO and RECAT-EU wake separation standard, the hourly runway throughput can be improved by approximately 20% with implementing the dynamic wake separation standards. This will be a promising solution for improving runway operational efficiency for airports with constrained capacity and configurations.</div
PYXIS: A higly predictable toolchain for FPGA circuit production of advanced GNC algorithm
No full textInternational audienceThe configuration of Field-Programmable Gate Arrays (FPGAs) within the context of command law implementation for aerospace systems is a complex process. In a previous work, we proposed the use of dataflow programming languages as the input for the synthesis process and as an alternative to traditional hardware programming languages. The proposed translation flow has been demonstrated to be faster than current state-of-theart tools while simultaneously offering greater predictability in the inferred hardware component of the design. This paper extends this previous work, addressing identified challenges. A first one is related to the use of a generated circuit to perform Guidance, Navigation and Control (GNC) functions: the generated netlist requires synchronization to be used within a closedloop system. A second one concerns the generation of circuits for custom datatypes: target descriptions must be automatically generated to facilitate technology mapping. As a consequence, a novel toolchain is proposed, providing the capability to generate synchronised circuits with arbitrary precision for computation.</div
Procédé de cartographie d'un réseau à file d'attente IP, basé sur l'analyse passive en un point d'un réseau
No full textLa présente invention concerne un procédé de détermination de la topologie d'un réseau informatique comprenant une pluralité de noeuds, chaque noeud gérant, au niveau logique, des paquets entrants via une file d'attente propre à réguler l'émission des paquets sortant à un débit constant maximal prédéterminé, ledit procédé étant mis en oeuvre depuis un point d'observation dudit réseau informatique.La présente invention concerne également un programme d'ordinateur comportant des instructions logicielles qui, lorsqu'elles sont exécutées par un ordinateur mettent en oeuvre un tel procédé de détermination de la topologie d'un réseau informatique. La présente invention concerne également un dispositif électronique de détermination de la topologie d'un réseau informatique comprenant une pluralité de noeuds propre à mettre en oeuvre ledit procédé.La présente invention concerne le domaine des réseaux informatiques notamment pour des applications de télécommunication. Plus particulièrement, la présente invention est propre à être appliquée au segment sol utilisateur d'une constellation ou à un système de télécommunication satellite à passerelles multiples, ou encore à des réseaux de télécommunication terrestre.Par la suite, par réseau informatique, on entend une infrastructure physique composée de noeuds et de liens. Dans un réseau informatique, les noeuds utilisateurs transmettent des informations à destination d'un ou plusieurs autres noeuds. L'information est relayée de point en point par des noeuds routeurs jusqu'à sa destination finale.Dans de tels contextes, cartographier le réseau informatique utilisé est essentiel et déterminer la topologie du réseau revient à déterminer un graphe non pondéré illustrant les noeuds et liens du réseau.Autrement dit, une telle caractérisation d'un réseau informatique IP (de l'anglais Internet Protocol) consiste en la description de sa topologie (i.e. cartographie), de l'état de ses liens (e.g. leur niveau de charge) et de son fonctionnement (e.g. le trafic utilisateurs et protocoles de communication utilisés). Une telle cartographie est la première étape nécessaire qui permettra de mettre en évidence des dysfonctionnements potentiels pour en améliorer son exploitation
Un analyseur de spectre à balayage avec GNU Radio Companion
No full textInternational audienceCet article propose l'implémentation didactique d'un analyseur de spectre à balayage sous GNU Radio Companion (GRC). Nous y exposerons tout d'abord l'intérêt de ce type d'analyseur par rapport à l'utilisation de la classique Fast Fourier Transform (FFT). Puis, étape par étape, nous assemblerons l'analyseur en expliquant les traitements mis en oeuvre, avec le souci d'en faire comprendre les principes plutôt que les arcanes. L'affichage final du spectre se fera à l'aide d'un script Python externe à GRC. Cela nous donnera l'occasion d'utiliser un des mécanismes de transmission de données disponibles pour faire sortir GRC de sa « bulle »