Archives Ouvertes HAL
Toutes les publications de l'ENAC en direct.
All ENAC publications.
[hal-01526879] Convergence of an estimator of the Wasserstein distance between two continuous probability distributions
This article is dedicated to the estimation of Wasserstein distances and Wasserstein costs between two distinct continuous distributions $F$ and $G$ on $\mathbb R$. The estimator is based on the order statistics of (possibly dependent) samples of $F$ resp. $G$. We prove the consistency and the asymptotic normality of our estimators.
[hal-01449963] On a three dimensional vision based collision avoidance model
This paper presents a three dimensional collision avoidance approach for aerial vehicles inspired by coordinated behaviors in biological groups. The proposed strategy aims to enable a group of vehicles to converge to a common destination point avoiding collisions with each other and with moving obstacles in their environment. The interaction rules lead the agents to adapt their velocity vectors through a modification of the relative bearing angle and the relative elevation. Moreover the model satisfies the limited field of view constraints resulting from individual perception sensitivity. From the proposed individual based model, a mean-field kinetic model is derived....
[hal-01521890] Knowledge Discovery in Graphs Through Vertex Separation
This paper presents our ongoing work on the Vertex Separator Problem (VSP), and its application to knowledge discovery in graphs representing real data. The classic VSP is modeled as an integer linear program. We propose several variants to adapt this model to graphs with various properties. To evaluate the relevance of our approach on real data, we created two graphs of different size from the IMDb database. The model was applied to the separation of these graphs. The results demonstrate how the model is able to semantically separate graphs into clusters.
[hal-01512448] Signal Quality Monitoring for New GNSS Signals
In the context of GNSS signals and associated augmentation systems modernization, new modulations are envisaged. More precisely Galileo E1C, the pilot component of the E1 Open Service signal (CBOC(6,1,1/11) modulation), Galileo E5a and GPS L5 (BPSK(10) modulation) are signals that will be used by civil aviation airborne receivers for pseudorange computation. To meet stringent requirements defined for civil aviation GNSS receivers, the characterization of distortions which could affect a GNSS signal in a hazardous way is required. In particular, expected signal distortions generated at payload level are described by Threat Models (TM). Distortions incorporate in the TM...
[hal-01522246] System simulation of a fleet of drones to probe cumulus clouds
Simulation plays an essential role in the development of complex systems. This paper reports on the development of a simulation infrastructure for a fleet of UAVs conceived to probe clouds, using an adaptive sampling scheme that calls for cloud mapping and trajectory planning. The mission is presented, the global approach to solve it and the ensemble of required processes are sketched. An overall simulation architecture is then depicted, and the details of its development using the Robot Operating System (ROS) are presented.
[hal-01522250] Adaptive sampling of cumulus clouds with UAVs
This paper presents an approach to guide a fleet of Unmanned Aerial Vehicles to actively gather data in low-altitude cumulus clouds with the aim of mapping atmospheric variables. Building on-line maps based on very sparse local measurements is the first challenge to overcome, for which an approach based on Gaussian Processes is proposed. A particular attention is given to the on-line hyperparameters optimization , since atmospheric phenomena are strongly dynamical processes. The obtained local map is then exploited by a trajectory planner based on a stochastic optimization algorithm. The goal is to generate feasible trajectories which exploit air flows to perform energy-...
[hal-01522067] Cognitive Maps Exploration trough Kernel Density Estimation
Currently approximately 860,000 people are affected by Alzheimer’s disease in France. This is why the study of Alzheimer’s disease has been identified as a major societal challenge. In the PAQUID cohort study, subjects performed a lexical evocation task by saying the maximum number of city names within 3 minutes. This task is directly related to the concept of cognitive map. The analysis of the list created by this task provides a unique opportunity to study the spatial mental representation of geographical space for elderly people before and after developing the dementia. We visualized graphs of this list by connecting cited city with a line. Since these graphs become...
[hal-01521988] Advanced decision aids for Air Traffic Controllers : Understanding different working methods from a cognitive point of view
This paper presents some experimental results about a major air traffic controllers' cognitive process while working with a new decision support system called Erato. This project is developed by the French Research Center for Civil Aviation (CENA). We are aiming at getting a good level of understanding of how controllers use the main functions of the system, so as to ensure relevant improvements in the future. Results are organized in two sections. Firstly, we present some results about unexpected use of the system and of various working methods with Erato. Secondly, our objective is to show that this use of the system can be explained in part by cognitive processes that...
[hal-01519659] Assessing the Robustness of a UAS Detect & Avoid Algorithm
In this article, we evaluate the robustness of a detect and avoid algorithm designed for the integration of UASs in terminal control areas. This assessment relies on a realistic modeling of navigation accuracy on positions and velocities and was carried out on thousands of scenarios built from recorded commercial traffic trajectories. The tested scenarios involved two different types of UASs – flying at 80 kts and 160 kts – with various missions, and three strategies for separation: one focussing on the separation distance, one focussing on the UAS mission and and combination of both. Fast-time simulation was used to evaluate each scenario against a wide range of...
[hal-01516696] Performance Assessment of a New Routing Protocol in AANET
Routing is a critical issue in mobile ad hoc networks. The routing algorithm must take into account the specific properties of the network such as its topology, the mobility of the nodes and their number. In this paper, we present a simulation-based study of the performances of our innovative routing protocol named NoDe-TBR (Node Density TBR) that takes into account the actual node density distribution. The considered ad hoc network is an Aeronautical Ad hoc NETwork (AANET), a future communication system enabling air↔air and air↔ground communications beyond the radio range of the sender. This context and the communication architecture have been modeled in a realistic way...