A Tailsitter UAV Based on Bioinspired, Tendon-Driven, Shape-Morphing Wings with Aerofoil-Shaped Artificial Feathers

Abstract

Unmanned aerial vehicles (UAVs) have revolutionised various industries, such as agriculture, remote sensing, and infrastructure inspection. To explore new designs and improve UAV flight performance, roboticists are seeking inspiration from nature. In this paper, we present a bioinspired tailsitter UAV utilizing shape-morphing wings with aerofoil-shaped artificial feathers. The design of the UAV is inspired by the shape and motion of bird wings, which can change their shape and span to adapt to different flight conditions. The pigeon's wing skeletal structure serves as the basis for the design, and the wing was developed to be fully tendon-driven employing a single motor for each side. The wings can contract and extend, resulting in a contraction ratio of 49% of the extended wing span. In hovering flight mode, the wing contraction shows a 42% decrease in drag for improved wind disturbance rejection. Wind tunnel testing characterises the wing's aerodynamic performance, revealing significant deflection at high angles of attack due to the articulated skeletal structure. The wings demonstrate low power consumption, averaging only 5.1 W during morphing in experiments. Finally, we demonstrate the wing's robustness through outdoor flight experiments. The research findings provide insights into the potential of bioinspired designs for tailsitter UAVs and offer a promising avenue for future research in this field.