Computer-based Real-Time Damaged Aicraft Model Identification with Two Step Method and Modified Stepwise Regression

Thomas Lombaerts,Faculty of Aerospace Engineering, Delft University of Technology, The Netherlands

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, performed jointly by the Faculty of Aerospace Engineering and Delft Center of Systems and Control (DCSC), which investigates the possibilities of adaptive control methods for recovering damaged aircraft op-erating 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 para-metric 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 asym-metric 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 identi-fication method in this study is based upon the so-called two step method, which has been continuously under development at Delft University of Technology over the last 20 years. Using modified stepwise regression, the two step method can be extended in order to develop the aerodynamic model structure specifically for the occurring failure mode. This method has been applied on the failure scenario of the EL AL Boeing 747 of flight 1862 which crashed in the Bijlmermeer in Amsterdam. Future work will include further investigations on the capa-bilities and eventual modifications on the current status of the two step method, as well as the implementation of this resulting real time damaged aircraft model in an adaptive control strat-egy.
The work in this paper is also closely related to the work in a European research project. The Group for Aeronautical Research and Technology in Europe (GARTEUR) has installed action group AG16 with the specific goal to investigate the possibilities of fault tolerant control in aeronautics and to compare the results of different reconfiguring control theories applied on a reference benchmark scenario, inspired by the same Bijlmermeer disaster mentioned above. The faculty of Aerospace Engineering as well as DCSC are partners in this research project too.