Archives Ouvertes HAL

Toutes les publications de l'ENAC en direct.
All ENAC publications.

[hal-01432789] In-Flight Thrust Measurement using On-Board Force Sensor

Publications ENAC - Friday, 20 January 2017 - 17:21:11
Preliminary results of an in-flight thrust measurement method are presented in order to determine the drag force. Flight experiments are conducted by an off-the-shelf aircraft which has been equipped with an autopilot system and additional sensors measuring the electric motor rotation speed, battery voltage, drawn current, and direct thrust of the motor. Several level cruise flights have been performed in order to measure the thrust, thus the drag force generated by the aircraft. The propulsion system used on the aircraft is first characterized in the wind-tunnel. The direct thrust measurement system which is on-board the aircraft presents a lot of noise coming from...

[hal-01432814] Maximizing the number of conflict-free aircraft using mixed-integer nonlinear programming

Publications ENAC - Tuesday, 17 January 2017 - 18:46:38
We address the conflict detection and resolution problem in air traffic control, where an aircraft conflict is a loss of separation between aircraft trajectories. Conflict avoidance is crucial to ensure flight safety and remains a challenging traffic control problem. We focus on speed control to separate aircraft and consider two approaches: (i) maximize the number of conflicts resolved and (ii) identify the largest set of conflict-free aircraft. Both problems are modeled using mixed-integer nonlinear programming and a tailored greedy algorithm is proposed for the latter. Computational efficiency is improved through a pre-processing algorithm which attempts to reduce the...

[hal-01414548] Mixed-Integer Nonlinear Programming for Aircraft Conflict Avoidance by Sequentially Applying Velocity and Heading Angle Changes

Publications ENAC - Tuesday, 17 January 2017 - 18:40:31
We consider the problem of aircraft conflict avoidance in Air Traffic Management systems. Given an initial configuration of a number of aircraft sharing the same airspace, the main goal of conflict avoidance is to guarantee that a minimum safety distance between each pair of aircraft is always respected during their flights. We consider aircraft separation achieved by heading angle deviations, and propose a mixed 0-1 nonlinear optimization model, that is then combined with another one which is based on aircraft speed regulation. A two-step solution approach is proposed, where the two models are sequentially solved using a state-of-the-art mixed-integer nonlinear...

[hal-01434172] Estimation non linéaire basée sur la théorie des observateurs invariants

Publications ENAC - Tuesday, 17 January 2017 - 16:04:50
Le travail effectué au cours de cette étude vise à analyser une solution algorithmique d’estimation non linéaire récemment développée : l’IUKF (Invariant Unscented Kalman Filter). A l’instar des travaux menés il y a quelques années autour de l’IEKF (Invariant Extended Kalman Filter), les gains de correction de cet estimateur, construits pour être invariant, peuvent être obtenus en suivant les étapes de calcul propres au filtrage de type UKF (que celles-ci soient déclinées dans une forme factorisée ou non). Toutefois, l’intégration à la théorie des observateurs invariants d’une procédure de calcul des gains de correction qui suit un schéma algorithmique emprunté au...

[tel-01430980] Processing and Integrity of DC/DF GBAS for CAT II/III Operations

Publications ENAC - Monday, 16 January 2017 - 17:59:01
In Civil Aviation domain, to cope with the increasing traffic demand, research activities are pointed toward the optimization of the airspace capacity. Researches are thus ongoing on all Civil Aviation areas: Communication, Navigation, Surveillance (CNS) and Air Traffic Management (ATM). Focusing on the navigation aspect, the goals are expected to be met by improving performances of the existing services through the developments of new NAVigation AIDS (NAVAIDS) and the definition of new procedures based on these new systems. The Global Navigation Satellite System (GNSS) is recognized as a key technology in providing accurate navigation services with a worldwide coverage...

[hal-01424922] The Analysis of Impact of Larger Aircraft A-380 on Frequency of Flights

Publications ENAC - Thursday, 12 January 2017 - 15:22:38
An innovations in airline industry has significant impact on the behavior of its participants: airline companies, airports and passengers. In this paper the innovation that is studied is an introduction of double-deck plane – A-380, which is currently the largest aircraft. Due to its size, it is able to carry at once approximately twice as many passenger as the other medium-sized aircraft, thus, allowing to reduce the frequency, and, as a consequence, induce lower environmental impact. However, in reality, flight frequency depends on many other factors such as airport fees, demand and strategic decision of companies to maximize their profits under competition. Using the...

[hal-00918054] Using BV-norm to Classify the Vasculitis in Multiple Sclerosis Fundus Angiography for Ophthalmologists

Publications ENAC - Thursday, 12 January 2017 - 13:28:44
Retinal diseases are causing alteration of the visual perception leading sometimes to blindness. For this reason early detection and diagnosis of retinal pathologies is very important. Using digital image processing techniques, retinal images may be analyzed quickly and computer-assisted diagnosis systems may be developed in order to help the ophthalmologists to make a diagnose. This paper describes the method using BV norm for classification of vasculitis fundus angiography. We propose a method to help ophthalmologists for the diagnosis of such autoimmune disease. Our study aimed to determine potential angiography details in intermediate uveitis helping to diagnose...

[hal-01424284] Fuzzy Risk Assessment for Airport Strategic Planning

Publications ENAC - Thursday, 5 January 2017 - 18:49:06
Airports are asset-intensive businesses that require a large amount of time to recover the significant financial investments in specific infrastructure such as runways and terminals. Airports investors must perform strategic moves based on calculated risks before taking investment decisions. This communication puts forward a new approach for airport investment risk assessment. The approach takes explicitly into account the degree of uncertainty in activity levels prediction and proposes milestones for the different stages of the project for minimizing risk. Uncertainty is represented through fuzzy dual theory and risk management is performed using dynamic programming

[hal-01422736] Distributed scaling control of rigid formations

Publications ENAC - Tuesday, 3 January 2017 - 12:04:29
Recently it has been reported that biased range measurements among neighboring agents in the gradient distance-based formation control can lead to predictable collective motion. In this paper we take advantage of this effect and by introducing distributed parameters to the prescribed interdistances we are able to manipulate the steady-state motion of the formation. This manipulation is in the form of inducing simultaneously the combination of constant translational and angular velocities and a controlled scaling of the rigid formation. While the computation of the distributed parameters for the translational and angular velocities is based on the wellknown graph rigidity...

[hal-01418171] Integration of UAS in Terminal Control Area

Publications ENAC - Wednesday, 21 December 2016 - 20:21:50
In this article, we test a horizontal detect and avoid algorithm for UASs flying in Terminal Control Areas. We have used recorded commercial traffic trajectories and randomly built thousands of conflict scenarios with UASs to check the ability of such an algorithm to ensure the separation with commercial aviation. We consider two different types of UASs, flying at 80kn or 160kn, with six different missions: flying straight or turning and leveled, climbing or descending. We only focus on horizontal maneuvers at constant speed in order to not interfere with the TCASs of aircraft, nor rely on most UASs poor ability to change speed. The article investigates the influence of...
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