Antti Leinonen 2012 - Application for Inverse Simulation of Flight Tracks - Series

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Antti Leinonen Name of the publication Application for Inverse Simulation of Flight Tracks Publisher School of Engineering Unit Department of Applied Mechanics Series Aalto University publication series SCIENCE + TECHNOLOGY 8/2012 Field of research Aeronautical Engineering Abstract An application for inverse simulation of flight tracks is implemented. Such an application is required for analysis of flight accidents and verification of flight tracks that are generated using optimization methods. The application could also be used to support monitoring of aircraft fatigue life through the flight parameters. The application is required to utilize a simplified aerodynamic model to analyse flight tracks that are given in the form of the aircraft position at successive time steps. Such data from actual flights could be recorded using a GPS device or a radar. The most recognized inverse simulation methods are reviewed. The method selected for this work is based on successive numerical differentiation of the flight track to obtain velocity and acceleration vectors. To obtain a solution for the flight attitude, coordinated flight is assumed, i.e. the aircraft has no sideslip or side force. The contribution of the thrust to the lift is considered, and a technique is formulated to recognize the sections of the flight track flown using a negative load factor. Also the wind conditions are considered. The application is implemented in the Matlab® environment. The inverse simulation is verified using data from flight simulations. It is shown that the results of the inverse simulation are accurate if the initial data are accurate and the assumption of coordinated flight is valid. The flight parameters that are computed via the inverse simulation include speed, Mach number, thrust setting, angle of attack, Euler angles, angular rates and load factor vector. Data from actual flights may require processing, i.e. smoothing and filling, before good results can be obtained.An application for inverse simulation of flight tracks is implemented. Such an application is required for analysis of flight accidents and verification of flight tracks that are generated using optimization methods. The application could also be used to support monitoring of aircraft fatigue life through the flight parameters. The application is required to utilize a simplified aerodynamic model to analyse flight tracks that are given in the form of the aircraft position at successive time steps. Such data from actual flights could be recorded using a GPS device or a radar. The most recognized inverse simulation methods are reviewed. The method selected for this work is based on successive numerical differentiation of the flight track to obtain velocity and acceleration vectors. To obtain a solution for the flight attitude, coordinated flight is assumed, i.e. the aircraft has no sideslip or side force. The contribution of the thrust to the lift is considered, and a technique is formulated to recognize the sections of the flight track flown using a negative load factor. Also the wind conditions are considered. The application is implemented in the Matlab® environment. The inverse simulation is verified using data from flight simulations. It is shown that the results of the inverse simulation are accurate if the initial data are accurate and the assumption of coordinated flight is valid. The flight parameters that are computed via the inverse simulation include speed, Mach number, thrust setting, angle of attack, Euler angles, angular rates and load factor vector. Data from actual flights may require processing, i.e. smoothing and filling, before good results can be obtained.