Dynamics analysis, control and flight test of all-wing tail-sitter configuration solar powered UAV

This paper proposes a novel all-wing tail-sitter Vertical Take-off/Landing (VTOL) solar-powered Unmanned Aerial Vehicle (UAV) configuration. It adopts thrust differential control instead of traditional aerodynamic control surfaces to maximize the solar panel layout area and the photovoltaic energy-harvesting power. Compared to conventional electric VTOL (eVTOL) aircraft, this design achieves over sixfold improvement in endurance. To address insufficient control effectiveness caused by the large wingspan and low wing loading, a variable thrust installation angle is designed. A dynamic model incorporating the propulsive-aerodynamic coupling effects between the propeller slipstream and the wing, along with the thrust installation configuration, is developed. Detailed stability and maneuverability analysis demonstrates that, the designed thrust installation angle effectively enhances roll control authority during VTOL phases and benefits longitudinal static stability in level flight, without significantly compromising dynamic stability. Aiming at the nonlinear propulsive-aerodynamic coupling and model errors, an INDI-based unified attitude control law is designed and evaluated through simulations and full-envelope flight tests, confirming the control effectiveness and configuration feasibility. Furthermore, the maximum endurance performance of the prototype is discussed based on the power data collected during flight and the numerical model of solar irradiance.