Pilot-Assist Landing System for Hover-Capable Fixed-Wing Unmanned Aerial Vehicles in All Flight Regimes

Abstract

This work presents an integrated guidance and control system designed to assist a remote human operator during the landing operation of a hover-capable fixed-wing aircraft. These platforms are capable of both conventional, steady flight and thrust-borne maneuvering, but are challenging to pilot. The proposed pilot-assist system is valid for both flight regimes, including transitions between them, and enables the pilot to intuitively adjust the landing approach, re-position if necessary, and select between conventional and vertical landing. The control system is constructed around a nonlinear SO(3) attitude control system, together with a nonlinear position controller valid for all flight regimes. A guidance algorithm is developed around the control system that translates pilot inputs into references in an intuitive manner. System performance is verified through numerical simulation using a high-fidelity model of an agile fixed-wing aircraft. Results show the proposed system enables a remote operator to safely land the aircraft while retaining high level authority during the procedure.