Dynamic Inversion-Based Control Design for Multi-Phase Tandem Tilt-Wing Flight

Abstract

The attractiveness of (tandem) tilt-wing electric vertical take-off and landing (eVTOL) vehicles has increased over the past decade due to their efficient wing-borne cruise flight and reduced requirements on ground-based infrastructure. However, this results in a complex flight control task, which must cover both the hover and cruise regimes, as well as the transition between them. In this regard, nonlinear dynamic inversion-based control approaches have been demonstrated to offer an effective solution. The intrinsic characteristics of these vehicles require that the controller operates across multiple flight phases, which differ in their dominant dynamics. This necessitates the implementation of multi-phase control strategies and a corresponding design approach. Dynamic inversion decouples the dynamics, providing a clean interface to the higher-level control functions. Furthermore, the controller is extended to utilize the pitch channel complementary to the tilt angle. The control system is evaluated on a six-degree-of-freedom flight dynamic model based on strip theory. The results demonstrate that the system is capable of performing a full transition. Additionally, pitch-supported tilting extends the flight envelope and accelerates the transition maneuver.