Optimisation des trajectoires verticales par la méthode de la recherche de l'harmonie

Abstract

Faced with global warming, needs to find solutions to reduce CO2 emissions are urgent, especially when considering the growth in air travel during recent decades. Trajectory optimisation is one of the ways to reduce fuel consumption during a flight. In order to determine the optimal trajectory of the aircraft, several algorithms have been developed. The aim of these algorithms is to reduce the total cost of flight which is directly related to the consumption of fuel and flight time. Another parameter, named cost index is considered in the definition of the cost of flight. Fuel consumption is given by a performance database for each flight phase. In the case of this thesis, phases for a complete flight, including climbing, cruising and descent, are studied. A “step climb” is defined as a short climb of 2 000ft during the cruise phase is also studied. The algorithm developed in this thesis is a metaheuristic algorithm named Harmony Search (HS) which combines two types of research: local search-based and population-based giving it a significant advantage. The algorithm is based on the search for a perfect state of harmony as is the case with music. The aim being to identify the most pleasant auditory experience, otherwise put, the best harmony. In terms of the optimization problem, the best harmony can be compared to finding the cheapest cost of flight. Various input data such as the weight of the plane, destination, initial speed of the plane and the number of iterations must be, among others, provided as input for the algorithm in order to be able to determine the optimal solution that is defined as: [Climb speed, Altitude, Cruise speed, Descent speed]. The algorithm was developed using MATLAB and tested for various destinations and weight of plane for one type of aircraft. Algorithm based results were validated, initially, with results obtained from an exhaustive research that used all possible combinations. This exhaustive research provided the global optimal which was treated as a target value for Harmony Search optimal. Another comparison was completed between results from the algorithm and results from the Flight Management System (FMS) which is an on-board avionics system located in the cockpit, used to determine the flight path in order to optimize trajectory. The goal is to prove that the harmony search gives better results than the algorithm implemented in the FMS.

Date	10 Jan 2017
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Ruxandra Botez (Supervisor)