Adaptive Nonlinear Flight Control of STOL-Aircraft Based on Incremental Nonlinear Dynamic Inversion

Abstract

In this paper an adaptive control system for a passenger aircraft with active high-lift system is presented. Failures in the high-lift system parts of such aircraft are critical and consequently need to be handled automatically. An adaptive controller is proposed which consists of incremental nonlinear dynamic inversion (INDI) with a reference model and linear controller. As the INDI is adaptive against uncertainties or system failures, no additional adaptive element like a neural network is needed. The implementation of the INDI requires a nonlinear system model which is permanently linearized during the runtime in order to obtain the current input matrix which here basically consists of the control surfaces effectiveness. It also requires feedback of the translational and rotational acceleration measurements which usually suffer from noise. In order to test the adaptivity of the INDI, a partial failure of the high-lift system during the landing approach is regarded. It shows that the INDI is capable of compensating the error by only using the conventional control surfaces.