Online self-monitoring of automatic take-off and landing control of a fixed-wing UAV

In comparison to the pilot aboard a manned aircraft, the flight operator of an unmanned aerial vehicle (UAV) has less possibilities to supervise its automatic flight guidance and control system and intervene if necessary. This is especially critical during automatic take-off and landing (ATOL), as these phases of flight demand low reaction time and tolerate little error. This paper presents an online self-monitoring algorithm for the ATOL system of a fixed-wing UAV. It assesses systems, controllers, and flight-performance during the maneuvers and enables automatic decision to alter or abort. The algorithm has been successfully implemented in the flight control system of the SAGITTA Demonstrator UAV, the functional software of which has been developed at the Institute of Flight System Dynamics of the Technical University of Munich. Simulation results and ground testing of the SAGITTA Demonstrator have proven the concept of the self-monitoring algorithm and give an outlook to its applicability in flight.