Pilot modeling and control augmentation for the XV-15 in in-ground-effect hover

Abstract

This paper presents design and simulation results related to pilot modeling and control augmentation for the NASA- Army-Navy-Bell XV-15 tilt rotor aircraft during hover in ground effect. Pilot models are developed using a c ombination of optimal and classical c ontrol theory. These models, when combined with the aircraft, its stability and control augmentation system (SCAS), and a g ust disturbance model, reproduce the flight test results observed during in-ground-effect (IGE) hover with good fidelity. Pilot work load is considered high with the present SCAS and there is a tendency toward pilot-induced oscillation (PIO). The control augmentation systems presented in this paper r educe pilot work load and the tendency toward PIO.