Eagle-Scale Flapping-Wing Robot with Aggressive Roll Maneuverability: Bio-Inspired Actuation, Fluid-Structure Interaction Simulation and Flight Experiment

Large flapping-wing aerial vehicles (FWAVs) face dual challenges in aerodynamic and structural design, with long-standing technical bottlenecks, particularly in roll maneuvers. In this study, by reverse-engineering the biomechanical mechanisms of raptor flight, we propose a bio-inspired wing-shoulder torsional mechanism and successfully developed an eagle-inspired flapping-wing aerial vehicle with a wingspan of 1.87m and a takeoff weight of 1,260g. A nonlinear explicit dynamics-lattice Boltzmann fluid-structure interaction (FSI) numerical model was innovatively established, comprehensively revealing the interaction mechanism between unsteady flapping flow fields and flexible wing deformations. Numerical simulations demonstrate that at a cruising speed of 8 m/s, the proposed mechanism generates a high-purity roll torque of 3.3 N·m (with a residual yaw torque of 0.2 N·m, torque purity ratio 16.5:1), while lift and thrust losses are below 1.5%. Flight experiments validate the exceptional performance of this mechanism in 3D maneuvers: a 360° barrel roll is completed in 2.6 seconds (average roll rate 136°/s). This study provides a theoretical framework and technological prototype for next-generation bio-inspired aerial vehicles that integrate efficient cruising with high maneuverability, marking the first instance where FWAVs surpass traditional aircraft in specific 3D maneuverability metrics.