Adaptive augmentation of incremental nonlinear dynamic inversion controller for an extended f-16 model

The objective of this paper is to design an adaptive augmentation for the baseline controller of an extended F-16 model to increase robustness in the presence of parametric uncertainties. The extended F-16 model having redundant inputs, with an incremental nonlinear dynamic inversion (INDI) baseline controller which was developed at the Institute of Flight System Dynamics, TUM, serves as the basis of this work. The INDI control law provides a linearized approximation of incremental plant dynamics and reduces dependence on model uncertainties. However, uncertainties in the form of estimation errors for current input matrix and output derivative along with unmodeled actuator dynamics need to be compensated. Therefore, in this paper, adaptive augmentation techniques such as SVD based update laws for predictor based model reference adaptive control and L₁ piecewise constant adaptation were implemented to achieve desired performance in presence of these uncertainties.