A fault tolerant control for iced aircraft based on fixed-time incremental dynamic inversion with FTESO

Icing seriously affects the aerodynamic coefficients and flight performance of an aircraft. To address this problem, in this paper a fixed-time incremental nonlinear dynamic inversion(INDI) control method based on a fixed-time dilated state observer(FTESO) is proposed, and a flight controller for a certain type of transport aircraft is designed based on this method, which is used to enhance the flight control capability under icing conditions, and thus improve the flight safety. In this designed controller, the FTESO is used to estimate the disturbance in the angular acceleration signal, which solves the problem that the robustness of the existing INDI control depends on the accuracy of the angular acceleration. Moreover, the control method can ensure that the aircraft state errors converge to a stable region in a fixed time, and the convergence time does not depend on initial errors. Simulation results show that the designed controller is able to overcome the effect of icing on the aircraft and ensure that the aircraft achieves the desired flight performance even in angular acceleration disturbances.