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Extending Guiding Vector Field to track unbounded UAV paths
No full textInternational audienceA recent advance in vector field path following is the introduction of the Parametric Guiding Vector Field method. It allows for singularity-free vector fields with strong convergence guarantees, usable even for self-intersecting paths. However, the method requires significant gain tuning for practical use. In particular, for unbounded paths, the gains will inevitably become ill-suited for efficient path following. We propose a method to overcome this issue by introducing a dynamic step adaptation strategy, which provides additional normalization properties to the field. This allows the following of unbounded curves and reduces the number of gains to tune. The proposed improvements are verified in simulations using the PaparazziUAV software
The Curse of Time Horizon in Detect & Avoid Algorithms
No full textInternational audienceThis paper introduces a centralized collision avoidance algorithm based on a Differential Evolution, for the purpose of studying the time horizon effect, a pathological behavior previously identified in Detect & Avoid (D&A) decentralized algorithms based on geometric methods. This pathological behavior, called time horizon effect, is most likely to occur during constant-speed encounters, when the lateral maneuvers issued by the D&A system postpone the crossing of trajectories beyond the horizon of conflict detection by maneuvering the flights toward parallel tracks. In such cases, the flights might end up locked on parallel tracks, missing their destination.The proposed centralized algorithm selects the best direction changes at each time step for all flights, with the primary objective to maintain a minimum separation between the flights.We show that the time horizon effect also occurs when using such a centralized optimization algorithm having full knowledge of the flight intents, and propose mitigating strategies. This suggests that the horizon effect is not related to the distributed nature of many D&A methods found in the literature, but is rather a more general effect due to the myopic nature of the decision process.</p
An In-Depth Examination of Mental Incapacitation and Startle Reflex: A Flight Simulator Study
No full textInternational audienc
CONSTRAINED ZONOTOPE ENCLOSING A STATE REPRESENTING MOTION OF AT LEAST ONE MOBILE TARGET GOVERNED BY A NONLINEAR MODEL
No full textA method for estimating a constrained zonotope enclosing a motion state of at least one mobile target , the method including : a ) linearizing a nonlinear transition model at an element of a first zonotope ( Z ( tk -1 ) ) , b ) computing transi tion linearization errors at different elements of the first zonotope ( Z_ ( tk -1 ) ) , c ) computing a second zonotope that contains all linearization errors , d ) propagating ( 102) the first zonotope so as to obtain an a priori zonotope ( ? ( t ) )enclosing the motion state at a second moment ( tz ) after the first moment ( tx -1 ) , wherein the a priori zonotope ( ? , ( t z ) ) is a linear projection of a hypercube , the hypercube being subject to at least one linear constraint , e ) updating ( 104) the a priori zonotope ( ? ( tx ) ) so as to obtain an a posteriori constrained zonotope ( Z-( tx ) ) enclosing the motion state at the second moment ( tz ) .</p
A survey on cryptographic methods to secure communications for UAV traffic management
No full textInternational audienc
Analyse des effets électromagnétiques des décharges Corona sur des systèmes sol de communications aéronautiques
No full textCorona discharges are phenomena of partial electrostatic discharges that can occur at the top of pylons or high metal structures, triggered by a large electric field gradient, as in bad weather conditions. Their effect was studied following the introduction of television antennas in the 1950s, because this phenomenon caused degradation of the quality of video reception when weather conditions became stormy. The installation of radomes on the antennas made it possible to solve the problems on the video channels. However, problems persist in the VHF band. Thus, in stormy conditions, some onboard/ground communications (VHF band) are strongly degraded by parasitic noises, the origin of which has been attributed to the corona discharge phenomenon. Solutions have been implemented but are not completely effective, due to lack of understanding of the triggering steps of discharges, propagation of parasitic currents and antenna / structure coupling. The aim of this thesis is to understand better the physical mechanisms of appearance and maintenance of these parasitic currents, to propose adapted technical solutions, including the design of current traps. On-site and laboratory measurement campaigns are planned. An important modeling work will also be done.Les décharges Corona sont des phénomènes de décharges électrostatiques partielles qui peuvent se produire au sommet de pylônes ou de structures métalliques élevées, déclenchées par un gradient de champ électrique important, comme en cas de mauvaises conditions climatiques. Leur effet a été étudié suite à l'implantation d'antennes télévision dans les années 50, car ce phénomène provoquait des dégradations de la qualité de la réception vidéo lorsque les conditions météorologiques devenaient orageuses. La mise en place de radômes sur les antennes a permis de résoudre les problèmes sur les canaux vidéo. Cependant, des problèmes persistent en bande VHF. Ainsi, en conditions orageuses, certaines communications bord-sol (bande VHF) sont fortement dégradées par des bruits parasites, dont l'origine a été attribuée au phénomène de décharges Corona. Des solutions ont été mises en place mais ne sont pas complètement efficaces, par manque de compréhension des étapes de déclenchement des décharges, de propagation de courants parasites et de couplage antennes/structure. L'objectif de cette thèse est de mieux comprendre les mécanismes physiques d'apparition et d'entretien de ces courants parasites, pour proposer des solutions techniques adaptées, avec notamment la conception de pièges de courants. Des campagnes de mesures sur site et en laboratoire sont prévues. Un important travail de modélisation sera également effectué
Gazealytics: A Unified and Flexible Visual Toolkit for Exploratory and Comparative Gaze Analysis
No full textInternational audienceWe present a novel, web-based visual eye-tracking analytics tool called Gazealytics. Our open-source toolkit features a unified combination of gaze analytics features that support flexible exploratory analysis, along with annotation of areas of interest (AOI) and filter options based on multiple criteria to visually analyse eye tracking data across time and space. Gazealytics features coordinated views unifying spatiotemporal exploration of fixations and scanpaths for various analytical tasks. A novel matrix representation allows analysis of relationships between such spatial or temporal features. Data can be grouped across samples, user-defined AOIs or time windows of interest (TWIs) to support aggregate or filtered analysis of gaze activity. This approach exceeds the capabilities of existing systems by supporting flexible comparison between and within subjects, hypothesis generation, data analysis and communication of insights. We demonstrate in a walkthrough that Gazealytics supports multiple types of eye tracking datasets and analytical tasks
Aircraft Conflict Resolution
No full textThis work was partly funded by the European Union’s Horizon 2020 Research and Innovation Program under the Marie Sklodowska-Curie Grant Agreement No. 764759 ETN “MINOA.”This publication was supported by the Chair “Integrated Urban Mobility,” backed by L’X – École Polytechnique and La Fondation de l’École Polytechnique. The partners of the Chair shall not under any circumstances accept any liability for the content of this publication, for which the author shall be solely liable
Minimal Communication between Drones Using Guidance Vector Fields in Dense Airspace
No full textInternational audienceIn response to escalating drone traffic, this paper investigates the interplay between drone density, communication frequency, and collision avoidance. We utilize artificial potential fields as a guidance mechanism for drones navigating in dense airspace. Through numerical simulations involving two to nine drones, we analyze how communication frequency correlates with collision rates as drone density increases. Our findings reveal the nuanced relationship between these variables, showing that communication frequency requirements increase with drone density for collision-free navigation. Furthermore, we present a theoretical framework predicting the relationship between drone density and the minimal communication frequency required for safe operations. We also demonstrate a simple experiment in the flying arena to highlight the influence of the rate of positional information sharing on the paths taken by drones
Modalités de collaboration à distance pour soutenir la conscience mutuelledans un contexte d'opération monopilote
No full textThis thesis addresses the issue of remote collaboration between a single on-board pilot and a ground pilot within the framework of the Single Pilot Operation (SPO) concept in commercial aviation. In the absence of suitable collaboration tools, mutual awareness between these two pilots is likely to deteriorate, potentially compromising flight safety. To restore this mutual understanding, pieces of information can be integrated into future flight tools. An initial study identifies mutual awareness problems by simulating remote collaboration between two pilots and identifies a number of these information elements. A second study evaluates design element prototypes to represent this information and explores two new interfaces ( extit{Mutual Awareness Extension Interfaces}, MAEI), one for the on-board pilot and the other for the ground-based pilot. Remote collaboration tests were conducted with four professional pilots to assess the effectiveness of the cues to be transmitted, the transmission modalities, and the representations used. Observing that pilots compensate for the lack of information through verbal communication, we finally examined the impact of cues informing about the on-board pilot's availability to regulate interruptions, particularly based on his mental workload. The goal is to demonstrate the importance of providing availability and mental workload information of the on-board flight pilot to optimize communication and collaboration with the ground pilot. In conclusion, this thesis highlights the role of mutual awareness in remote collaboration between pilots and proposes recommendations for designing suitable tools. These findings have implications for commercial aviation and pave the way for future research and developments in this field.Cette thèse aborde la problématique de la collaboration à distance entre un pilote unique en vol et un pilote au sol dans le cadre du concept de Single Pilot Operation (SPO) en aviation commerciale. En l’absence d’outils de collaboration adaptés, la conscience mutuelle entre ces deux pilotes est susceptible de se dégrader, ce qui peut compromettre la sécurité des vols. Pour rétablir cette compréhension mutuelle, des éléments d'information peuvent être intégrés dans les futurs outils de vol. Une première étude identifie les problèmes de conscience mutuelle en simulant une collaboration à distance entre deux pilotes et identifie un certain nombre de ces éléments d'information. Une seconde étude évalue des prototypes d’éléments de design pour représenter ces informations, et explore deux nouvelles interfaces ( extit{Mutual Awareness Extension Interfaces}, MAEI), l’une pour le pilote bord et l’autre pour le pilote au sol. Des tests de collaboration à distance ont été réalisés avec quatre pilotes professionnels pour évaluer l’efficacité des indices à transmettre, des modalités de transmission et des représentations utilisées. Constatant que les pilotes suppléent au manque d'information par la communication verbale, nous avons enfin examiné l’impact d’indices informant de la disponibilité du pilote bord pour réguler les interruptions, notamment en fonction de sa charge mentale. L’objectif est de démontrer l’importance d’offrir des informations de disponibilité et de charge mentale du pilote bord pour optimiser la communication et la collaboration avec le pilote sol. En conclusion, cette thèse met en évidence le rôle de la conscience mutuelle dans la collaboration à distance entre pilotes et propose des recommandations pour la conception d’outils adaptés. Ces résultats ont des implications pour l’aviation commerciale et ouvrent la voie à de futurs recherches et développements dans ce domaine