AbstractsTransportation

Ride comfort in commercial aircraft during formation flight using conventional flight control

by Evert Frederick Trollip




Institution: Stellenbosch University
Department:
Year: 2016
Keywords: UCTD; Aeronautics, Commercial; Airplanes  – Control systems; Formation flying; Aeronautics, commercial  – Management; Airplanes  – Control systems  – Design and construction
Posted: 02/05/2017
Record ID: 2127940
Full text PDF: http://hdl.handle.net/10019.1/98733


Abstract

ENGLISH ABSTRACT: Global market forecasts and rapid air transport growth are making the aeronautical industry become aware of the necessity to develop high capacity long-range and fuel-effi cient aircraft while maintaining high levels of passenger comfort. With the large interest in automated formation flight and improvements in automated flight control, it is the aim of this research to evaluate passenger ride comfort in commercial aircraft during formation flight. The main objective of this thesis is to take into account the aircraft dynamics, atmospheric turbulence and the effect of a flight control system when evaluating the ride comfort of passengers. To achieve this objective, a detailed literature study into current and past projects was performed, focusing on formation flight, passenger comfort evaluation and improvements in passenger comfort with e fficient control systems design. Following the literature study, a theoretical Boeing B747 aircraft model was built and tested in MATLAB and Simulink. Subsequently, a conventional model of the fly-by-wire architecture used in modern transport aircraft was designed, implemented, and verified in simulation. To model the formation flight effects, the induced forces and moments on the follower aircraft due to the trailing vortices of the leader were derived in a previous study by Bizinos at the University of Cape Town. These induced loads, expressed as aerodynamic coffe cients, were used in conjunction with the conventional aerodynamic model to produce an extended aerodynamic model for formation flight. The conventional fly-by-wire control architecture used by modern transport aircraft has been extended for formation flight of two or more aircraft, with the focus on two aircraft in right echelon formation. A full non-linear simulation with realistic turbulence was produced to verify the working of the extended controllers and to ensure the follower maintains its path behind the leader aircraft. In formation flight, the passenger comfort is in influenced by disturbance loads due to the turbulence, as well as by compensatory control inputs produced by the autopilot controllers. The accelerations of passengers in a seated position were determined by considering the passenger's seated position with respect to the mass centre, and the forces and moments at and around the mass centre respectively. These accelerations are weighted according to their frequency to determine the comfort levels in accordance with the International Organisation for Standardisation (ISO 2631-1). Simulation results of the accelerations experienced at different locations in the trailing aircraft of a formation showed that very little difference in comfort can be expected between the different formation flight aircraft under the same flight conditions. It was concluded for both aircraft that a seating location at the front of the aircraft is more comfortable than one at the back of the aircraft. During light and moderate turbulence, the overall acceleration magnitudes remained… Advisors/Committee Members: Engelbrecht, J. A. A., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering..