Real Time Damaged Aircraft Model Identification for Reconfiguring Flight Control

Abstract

This paper presents a study on the real time identification process of a damaged aircraft model. This is part of a Delft University research project which investigates the possibilities of adaptive control methods for recovering damaged aircraft operating in failure conditions. With help of a Boeing 747 simulation model supplied by the Dutch Aerospace Laboratory, including realistic failure modes with additive as well as parametric failures, it is possible to analyse the considered method’s capabilities to identify these types of damage. The types of failures included in the simulation model describe also asymmetric damage, resulting in a situation where it is impossible to base the damaged aircraft model upon the concept of decoupled longitudinal and lateral motions. The considered identification method in this study is the so-called two step method, which has been continuously under development at Delft University of Technology over the last 20 years. The two consecutive steps of this method, which are its important cornerstones, are presented: Aircraft State Estimation (ASE) and Aerodynamic Model Identification (AMI). Also two important validation tests of this method are illustrated. Furthermore, modified stepwise regression (MSWR) is introduced as a model structure development tool. Thereafter, as an application, some preliminary identification results are shown for damaged aircraft models. Future work will include further investigations on the capabilities and eventual modifications on the current status of these methods, as well as the implementation of this resulting real time damaged aircraft model in an adaptive control strategy.