Tilt-Wing Control Design for a Unified Control Concept

Urban Air Mobility (UAM) promises an economic and ecological solution for the growing mobility demand by utilizing Electric Vertical Take-off and Landing Vehicles (eVTOLs). Tilt-wing eVTOLs (e.g., Airbus A3 Vahana) appear to be the most promising ones because they offer an efficient wing-borne cruise flight while reducing the need for ground-based infrastructure at the cost of a complex control task. Tilt-wing vehicles increase the pilot's workload and introduce possible human and technical failures due to mechanical complexity. A unified control concept shall be able to handle the vehicle in every phase and provides a single clean and intuitive interface. This work develops a controller capable of decoupling the physical couplings of the flight dynamics. An integrated six-degree-of-freedom rigid body model in a compact mathematical representation is proposed, and flight control requirements are identified. An Incremental Nonlinear Dynamic Inversion (INDI) controller is designed which fulfills the requirements. Moreover, multiple command filters and outer-loop controllers are designed to handle different control modes and provide a proof-of-concept for a unified control scheme. Finally, the closed-loop system is evaluated by means of the control requirements and a generic UAM mission. The closed-loop system masters all parts of the mission and fulfills these requirements. The developed dynamic model and control system will be valuable for future tilt-wing eVTOL research, especially subsequent works on unified control systems