Accomodation of failures in the flight control system of the F-16 aircraft using adaptive control

Abstract

The effect of surface and hardware failure on the flight control system of the F-16 fighter aircraft is examined. In the absence of failures and unpredictable changes, the controller, which is based on gains scheduling, performs very well and exhibits a good degree of robustness even for high angles of attack. However, in the presence of failures its performance deteriorates severely. In order to accomodate possible failures and therefore maintain the good performance characteristics of the aircraft, the control system is augmented with a hybrid adaptive linear quadratic control scheme. The augmented adaptive flight control system has the capability of learning and accomodating online any drastic changes in the aircraft dynamics due to surface or hardware failure. The proposed flight control system was tested on a nonlinear model of the F-16 aircraft, and the simulation results demonstrate its ability to accomodate control failures and maintain good performance.