Assessment of the effect of the fuel savings scheme in Formation Flight Planning using Switched Optimal Control Techniques (original) (raw)
Related papers
Aircraft Route Optimization for Formation Flight
Journal of Aircraft, 2014
We quantify the fuel and cost benefits of applying extended formation flight to commercial airline operations. Central to this study is the development of a bi-level, mixed integer-real formation flight optimization framework. The framework has two main components: 1) a continuous domain aircraft mission performance optimization and 2) an integer optimization component that selects the best combination of optimized missions to form a formation flight schedule. The mission performance reflects the effects of rolled-up wakes, formation heterogeneity, and formation-induced compressibility. The results show that an airline can use formation flight to reduce fuel burn by 5.8% or direct operating cost by 2.0% in a long-haul international schedule. The savings increase to 7.7% in fuel or 2.6% in cost for a large-scale, transatlantic airline alliance schedule. These results include the effects of a conservative fuel reserve for formation flight. Sensitivity studies show that a modest reduction in the cruise Mach number may be sufficient to manage the impact of formation-induced compressibility effects on system-level formation flight performance. We demonstrate that the potential savings from extended formation flight-an operational improvement using existing aircraft-can approach those claimed for advanced vehicle technologies and unconventional configurations.
Fuel Planning Strategies Considering Operational Uncertainties of Aerodynamic Formation Flight
2021
The operational concept of aerodynamic formation flight, also referred to as aircraft wake-surfing for efficiency (AWSE), has high potential in terms of fuel savings and climate impact mitigation. In order to implement this concept, many technological and operational challenges have to be coped with. As the fuel consumption during a mission strongly depends on a successful execution of AWSE, the existing uncertainties regarding flight planning increase. While a conservative fuel planning ensures a follower to complete the mission even in the case of a formation failure, it might result in high amounts of excess fuel and, therefore, additional fuel consumption. In this study, this issue is addressed by the adaptation of flight planning procedures to the requirements of AWSE focusing on fuel planning in particular, considered from the perspective of a designated follower aircraft of a two-aircraft formation. This trade-off is modeled as an n-action two-event decision-making problem. E...
Formation Geometries and Route Optimization for Commercial Formation Flight
27th AIAA Applied Aerodynamics Conference, 2009
Formation flight provides an effective way to dramatically reduce fuel burn without fundamental changes to the aircraft flying today. A two aircraft echelon formation is investigated along with three different three aircraft formations. A three aircraft inverted-V formation geometry is shown to have many favorable characteristics compared to other formation geometries. All of the aircraft in this formation need very small aileron deflections to trim in roll, for most spanwise spacings the formation is statically stable, and the total formation induced drag is insensitive to high levels of positioning uncertainty. A trade study was conducted to determine the fuel savings and difference in flight times that result from applying formation flight to missions of different stage length and different spacings between the origin cities. For a two aircraft echelon formation, the maximum fuel savings were 4% with a tip-to-tip gap between the aircraft equal to 10% of the span and 10% with a tip overlap equal to 10% of the span. For the three aircraft inverted-V formation, the maximum fuel savings were about 7% with tip-to-tip gaps equal to 10% of the span and about 16% with tip overlaps equal to 10% of the span. A case study examined the use of formation flight on five FedEx flights from the pacific northwest to Memphis, TN. The purpose of this study was to quantify the fuel burn reduction achievable in a commercial setting without changing the flight schedule. With tip-to-tip gaps of about to 10% of the span it was shown that fuel savings of approximately 4% could be achieved for the set of five flights. With a tip-to-tip overlap of about 10% of the span the overall fuel savings are about 11.5% if the schedule is unchanged. This translates to saving approximately 700,000 gallons of fuel per year for the set of five flights. Nomenclature (x/b) Streamwise spacing between aircraft normalized by span (y/b) Spanwise spacing between aircraft normalized by span (y 1 /b) Spanwise spacing between left and middle aircraft in a three aircraft formation normalized by span (y 2 /b) Spanwise spacing between left and right aircraft in a three aircraft formation normalized by span (z/b) Vertical spacing between aircraft normalized by span (σ/b) Positioning uncertainty for trailing aircraft normalized by span Ratio of induced drag in formation to induced drag out of formation
Aircraft Route Optimization for Heterogeneous Formation Flight
53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference<BR>20th AIAA/ASME/AHS Adaptive Structures Conference<BR>14th AIAA, 2012
We examine the value of extended formation flight in the context of airline operations. The study is based on a bi-level route optimization framework. The aircraft performance model includes the e ects of rolled-up wakes, formation heterogeneity, and formationinduced compressibility e ects. We incorporate airline economics to understand the tradeo between speed and drag savings in the context of formation flight. The application of formation flight to a representative South African Airlines (SAA) long-haul route network can reduce fuel burn by over 4.6% or reduce direct operating cost by 2.1%. The savings increase to 6.8% in fuel or 2.4% in cost when we consider a large-scale Star Alliance transatlantic route network. Finally, the impact of compressibility on total fleet fuel and cost metrics is shown to be insignificant.
A Stochastic Switched Optimal Control Approach to Formation Mission Design for Commercial Aircraft
IEEE Transactions on Aerospace and Electronic Systems
En primer lugar, me gustaría expresar mi más sincera gratitud a Ernesto Staffetti, mi director. Gracias por tu guía, por todo tu tiempo, por tu esfuerzo y empeño en que este trabajo haya ido cogiendo forma y pueda estar orgullosa de él. Gracias por tener en cuenta mis opiniones siempre, por hacerme sentir escuchada y por todas las horas invertidas en cerrar cada fleco que quedaba suelto. Gracias también por tus ánimos y por tener siempre un rato para charlar de trivialidades. No puedo olvidar a Alberto Olivares, gracias. Tu ayuda para que esta tesis haya salido adelante es también incalculable. Gracias por ese nuevo punto de vista que siempre hacía replantear todo de nuevo, mejorándolo. Gracias por todos tus comentarios, por tu tiempo. Gracias por tu sinceridad y por tu buen hacer. I would like to thank Dr. Sander Hartjes, who supervised my stay at TU Delft. Thank you for your time and advice. It is a pity that my stay coincided with your academia departure. I would also like to thank all the people of the Air Transport & Operations group. Sin lugar a dudas, estos años y esta tesis no hubieran sido los mismos sin mis compañeros y compañeras de departamento. Gracias, en primer lugar, por los viernes de cerveza. No por la cerveza en sí, que también, sino por vuestra compañía. Sin duda, uno de los peores efectos colaterales de la pandemia, ha sido llevarse esos viernes. Gracias Mihaela, por ser la mejor compañera que se puede tener, pero sobre todo, por ser una gran amiga. Gracias Óscar, Edu, por escucharme, por vuestros consejos, por todos esos brindis y por los que nos quedan. Gracias Antonio, por tu confianza, por estar siempre dispuesto a echarme una mano. Gracias Fernando, por los ratos compartidos en el despacho entre viajes, escalada y montaña. Gracias Pepa, por la tensión compartida de estos últimos meses. Gracias Rebeca, Ana, Nacho, Álex, Cris, Estela, por cada charla. Gracias a todas y todos que, sin saberlo, me habéis ayudado a llegar hasta aquí. Gracias Jose, Laura, Elisa, Marta, Tere, Álex, por seguir haciendo el mundo girar. Gracias a ti en especial, Carlos, por ser como un hermano para mi. Gracias a todo el equipo Placax, a los super Saiyans, por las risas y por los pegues. Gracias a mi familia. Gracias tata, por estar ahí desde el primer día de mi vida. Gracias tío Félix, por mostrar siempre ese interés por mi y por mi trabajo. Gracias tío Basi, por enseñarme que siempre podemos aportar un granito de arena para hacer de este mundo algo mejor. Gracias papá y mamá, porque con vosotros los te quieros y los abrazos nunca son suficientes. Gracias por apoyarme siempre, gracias por haberme enseñado a creer en mi. Finalmente, a mi familia de bichitos. A ti, Juan, no puedo decirte simplemente gracias porque es insuficiente. Por ser mi amigo, mi compañero de viaje y de vida. Por los enanos. Porque contigo todo es más bonito. Y por supuesto, Lucas y Adriana, porque desde el primer segundo en el que os vi, supe que haría lo que fuera por veros sonreír. Esta tesis es vuestra. • Formation flight for a future highly efficient commercial aviation, financed by the Spanish Government (Reference code: TRA2017-91203-EXP). Universidad Rey Juan Carlos 2018-2021. Principal Investigator: Ernesto Staffetti. • Managing meteorological uncertainty for a more efficient air traffic system: Meteorological uncertainty processing and trajectory tracking, financed by the Spanish Government (Reference code: RTI2018-098471-B-C33). Consortium:
Energy optimal reconfiguration for large scale formation flying
… 2004. Proceedings of …, 2004
An efficient method for energy optimal reconfiguration of formation flying involving multiple spacecraft is presented. The idea is to introduce a set of way-points through which the spacecraft are required to pass combined with certain parameterization of the trajectories. The resulting energy optimal with collision avoidance constraints problem is formulated as a parameter optimization problem in terms of the way-points parameters. A numerical algorithm is proposed and used for scenarios with multiple spacecraft.
Optimal Trajectory Planning of Formation Flying Spacecraft
2005
Abstract: This paper introduces a closed-loop Guidance and Control optimal algorithm that balances the propellant consumption and the need for collision avoidance among formation ying spacecraft. This model-based algorithm is purely algebraic and computes the spacecraft trajectories from the knowledge of the formation linearized relative dynamics equations and the formation full state. Using Pontryagins maximum principle, Guidance generates the control inputs required to obtain the optimal trajectory from the current state until the target state, and does so for each of a set of regularly spaced time instants. After each recomputation, Control applies the optimal inputs until the next regularly spaced time instant, when Guidance updates the optimal trajectory again. Simulation results for the algorithm applied to a 3-spacecraft formation in GTO are presented. Copyright c 2005 IFAC
11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, 2011
Formation flying is introduced as a new and innovative air transportation system for long-haul commercial flight. With this paper the operational feasibility of formation flying is addressed, both from a market demand and economic, as well as an air traffic control perspective. Preliminary results of a case study indicate that operating a newly designed aircraft that is optimized for formation flying could cut the fuel consumption over long-haul flights in half compared to current state-of-the-art aircraft. Therefore, this air transportation system proves to be a possible solution to the impending regulations and fines regarding the reduction of CO 2 emissions in aviation.
Formation Flight Optimization Using Extremum Seeking Feedback
Journal of Guidance, Control, and Dynamics, 2003
A comprehensive design procedure based on extremum seeking for minimum power demand formation ight is presented, the rst with performance guarantees. The procedure involves the design of a new wake robust formation hold autopilot and transformation of the closed-loop aircraft dynamics to a form in which a newly available rigorous design procedure for extremum seeking is applicable. The design procedure is applied to a formation of Lockheed C-5s, extending the use of maximum performance formation ight to large transports. By the use of available experimental wake data of the C-5, a model of the aircraft in the wake is developed that models aerodynamic interference as feedback nonlinearities. Thus, this work is also the rst to attain stable extremum seeking for a plant with nonlinear feedback. Optimal formation ight is attained by online minimization of an easily measurable objective, the pitch angle of the wingman.