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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimal control based method for design and analysis of continuous descent arrivals

Park, Sang Gyun 12 January 2015 (has links)
Continuous Descent Arrival (CDA) is a procedure where aircraft descend, at or near idle thrust, from their cruise altitude to their Final Approach Fix without leveling off. By eliminating inefficient leveling off at low altitude, CDA provides benefits such as fuel savings, flight time savings, and the significant noise reduction near airports, but the usage of CDAs has been limited in low traffic condition due to difficulty in the separation management. For the successful CDA without degradation of the runway throughput, air traffic controllers should know the performance bound of the CDA trajectory and control the time of arrival for each aircraft, which is interpreted as Required Time of Arrival (RTA) from the aircraft standpoint. This thesis proposes a novel trajectory optimization methodology to meet RTA constraint. The CDA trajectory optimization problem in the flight management system is modeled as a path constrained optimal control problem of switched dynamical system. A sequential method that performs mode sequence estimation and parameter optimization, sequentially, is proposed to solve this problem. By analyzing the relaxed optimal solution with simplified dynamics, a computationally efficient algorithm to find the optimal switching structure is proposed and applied for the mode sequence estimation. This thesis also proposes a performance-bound analysis methodology using optimal control techniques to help controllers make a feasible schedule for CDA operations at a meter fix. The feasible time range analysis for a wide variety of aircraft is performed by using the proposed methodology. Based on the analysis result, a single flight time strategy is proposed for the application of CDA in high traffic conditions. The simulation with real traffic data has been shown that the single flight time strategy, combined with the proposed fixed RTA trajectory optimization, guarantees the conflict free CDA operation.
2

Formation Flight and Deformation Operational Trajectory Planning for Aircraft System

Haris, Muhammad 11 1900 (has links)
This thesis presents a comprehensive framework and a study for trajectory optimization based on the patterned formation flying of the aircraft system as well as the maneuvers for deforming the configured and aligned aerial vehicles with safe mode criteria considerations while subjected to typical environmental requirements of aerial-flying zones. The elementary trajectory problem of a simple dynamical point-mass system of the aircraft is mathematically formulated and converted into a simulation version of mathematical programming as finite horizon planning and fixed arrival time planning strategies as an optimization problem. The methodology of the designed framework is mainly concerned with the safer path planning of the aircraft system with testing on all the probable feasibility and safety constraints to incorporate into a mathematical programming design of a collision-free and optimal trajectory characterization. The imperative notion is to create a configurational pattern of the aircraft system based on their creation of wingtip vortices. Flying the aircraft in formation lessen the fuel consumption as well as increase the time efficiency. The aircraft formation is arranged and optimized for safe trajectories during flight operations and for reduction of the carbon footprint of the whole system. Furthermore, deformation maneuvers are incorporated to complete the aircraft planning system by allowing the possibility of safely disassembling the formation for emergency breakout and exit sequences.
3

Wind models and stochastic programming algorithms for en route trajectory prediction and control

Tino, Clayton P. 13 January 2014 (has links)
There is a need for a fuel-optimal required time of arrival (RTA) mode for aircraft flight management systems capable of enabling controlled time of arrival functionality in the presence of wind speed forecast uncertainty. A computationally tractable two-stage stochastic algorithm utilizing a data-driven, location-specific forecast uncertainty model to generate forecast uncertainty scenarios is proposed as a solution. Three years of Aircraft Communications Addressing and Reporting Systems (ACARS) wind speed reports are used in conjunction with corresponding wind speed forecasts from the Rapid Update Cycle (RUC) forecast product to construct an inhomogeneous Markov model quantifying forecast uncertainty characteristics along specific route through the national airspace system. The forecast uncertainty modeling methodology addresses previously unanswered questions regarding the regional uncertainty characteristics of the RUC model, and realizations of the model demonstrate a clear tendency of the RUC product to be positively biased along routes following the normal contours of the jet stream. A two-stage stochastic algorithm is then developed to calculate the fuel optimal stage one cruise speed given a required time of arrival at a destination waypoint and wind forecast uncertainty scenarios generated using the inhomogeneous Markov model. The algorithm utilizes a quadratic approximation of aircraft fuel flow rate as a function of cruising Mach number to quickly search for the fuel-minimum stage one cruise speed while keeping computational footprint small and ensuring RTA adherence. Compared to standard approaches to the problem utilizing large scale linear programming approximations, the algorithm performs significantly better from a computational complexity standpoint, providing solutions in fractional power time while maintaining computational tractability in on-board systems.
4

Planification de trajectoires avion : approche par analogie lumineuse.

Dougui, Nour Elhouda 15 December 2011 (has links) (PDF)
Dans le cadre du projet européen SESAR, la nécessité d'accroître la capacité du trafic aérien a motivé la planification de trajectoires avions 4D (espace + temps). Afin de mettre en place une planification pré-tactique (évitement de zones avec une mauvaise météo ou congestionnées pour un avion) et de mettre en place une planification tactique (générer des ensembles de trajectoires 4D sans conflit), nous introduisons un nouvel algorithme : l'algorithme de propagation de la lumière (APL). Cet algorithme est basé sur une méthode de propagation de front d'onde qui s'inspire de l'analogie avec la propagation de la lumière et qui est adapté au problème de planification de trajectoires. L'APL donne des résultats satisfaisant pour une journée de trafic réel sur la France tout en satisfaisant les contraintes spécifiques à la gestion du trafic aérien. L'APL a ensuite été adapté pour prendre en compte les incertitudes qui concernent la vitesse réelle des avions. Ainsi adapté aux incertitude, l'APL a été testé sur la même journée de trafic avec mise en place de points RTA (Real Time Arrival). Les points RTA permettent de réduire l'incertitude dans le cas où l'APL n'arrive pas à résoudre les conflits. Les résultats obtenus sont très encourageants.
5

Qu'est-ce que naviguer ? : analyse d'une tâche de pilotage comme préalable à la conception d'un système d'aide à la gestion d'un vol / What is the navigation task ? : analysis of a piloting task in order to design a new flight management system

Lacabanne, Marie 17 December 2014 (has links)
Cette étude est fondée sur deux constats dans le domaine du transport aérien : la conception des systèmes automatisés, et notamment du système de gestion de vol, découle d’un point de vue techno-centré ne prenant pas en compte le point de vue des opérateurs ; le système de gestion de vol est un système complexe entrainant une difficulté à l’appréhender pour optimiser l’accès aux fonctions existantes. Cette recherche a pour objectif de fournir des recommandations en vue de la conception d’une nouvelle interface du système de gestion de vol partant d’un point de vue centré sur l’opérateur. Pour cela, deux études ont été menées ayant pour objectif la réalisation d’une analyse cognitive de la tâche de navigation (tâche pour laquelle le système de gestion de vol a été initialement conçu). Pour ce faire, nous avons conduit des entretiens auprès de pilotes aux expériences diverses. Les résultats de ces deux premières études fournissent des éléments d’informations quant aux besoins informationnels des pilotes et nous informent aussi sur les exigences de la tâche et leur impact sur la conscience de la situation des pilotes. A la suite de ces résultats, des recommandations de conception pour une nouvelle interface de système de gestion de vol ont été émises visant à répondre aux besoins informationnels des pilotes et ainsi à améliorer leur conscience de la situation. Ces recommandations ont été testées lors d’une troisième étude. Les résultats enregistrés montrent que la réduction de l’effet de dissociation de l’attention ainsi que la contextualisation de l’information de manière cohérente par rapport à l’activité des pilotes permet d’améliorer leur conscience de la situation. / This study is based on two observations in the airway field: (i) the design of automated systems - particularly of the flight management system - is currently based on a techno-centered point of view that doesn’t take into account the user point of view; (ii) the flight management system is a complex system resulting in a long time of training and in a difficulty in both the knowledge and the access to the existing functions. This study aims to provide design recommendations for a new flight management system interface from the point of view of the pilots. In order to do this, two studies were carried out with the objective to produce a cognitive task analysis, and more particularly a cognitive task analysis of the navigation task (which is the task for which the system was initially created). Interviews were thus conducted with pilots with different experiences. The results of these two first studies provide information on the informational needs of the pilots, on the task requirements as well as on their impacts on the situation awareness of the pilots. Following these results, design recommendations for a new flight management system interface were produced in order to answer to the informational needs of the pilots and thus to improve their situation awareness. These recommendations were tested during a third study. The results show that the decrease of the attention dissociation’s effect as well as the consistency of the information contextualization of the pilot activity improves the situation awareness.
6

Flight Management System Model / Flight Management System Model

Franěk, Lukáš January 2011 (has links)
Diplomová práce shrnuje nejdůležitější informace o letectví, jako například základní používané termíny, popis letových fází apod. V této práci je popsán flight management system, jeho funkce a schopnosti vytvořit cenově příznivý a současně absolutně spolehlivý letový plán. V další části práce je nastíněna důležitost předpovědi počasí pro bezpečnou a současně cenově příznivou leteckou dopravu. Tato práce je vytvořena v programu Matlab a všechny bloky jsou naprogramovány jako m-funkce. Důležité části kódu jsou z důvodu názornosti zobrazeny jako vývojové diagramy. Praktická část práce je rozdělena do několika podkapitol, kde každá podkapitola popisuje jeden blok z blokového schématu pro výpočet nejistoty odhadované doby příletu. Současně je zde vysvětlena funkce ostatních bloků pro plánování letu, předpověď počasí, kombinování větrů a výpočet odhadnuté doby příletu a její nejistoty.

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