Aerodynamic performance of a bird-inspired morphing tail

Abstract

Flying animals such as insects, bats, and birds have acquired the ability to achieve diverse and robust flight patterns in various natural environments. Their sophisticated morphologies, kinematics, and dynamics have motivated engineers to develop bioinspired flying robots. Particularly, the capabilities of morphing wing and tail controls in birds have received significant attention. Such controls are expected to introduce novel mechanisms to achieve flight stabilization while maintaining high maneuverability with a low energy cost. While the control of tail posture and motion is considered to exhibit a significant influence on flight performance, there have been few studies focusing on control with multiple degrees of freedom in small flying robots. In this study, we developed a bird-inspired morphing tail mechanism; a model was fabricated and investigated its aerodynamic performance through wind tunnel experiments. The results indicate that the tail attitude can be controlled effectively to enable the enhancement of aerodynamic performance in terms of mechanical efficiency and controllability. We also verified that controlling the tail attitude is redundant in the control of aerodynamic force and moment production, implying the potential capability to achieve stable flight control strategies in response to various disturbances. Therefore, our results indicate that tail-attitude-based aerodynamic control may be able to cope with the conflicting requirements of improving stability and maneuverability of flyers.

3D-Printed Bio-Inspired Mechanisms for Bird-like Morphing Drones

“…Compared to the left-and right-hand tail planar morphing design of Murayama et al [19], symmetric planar morphing was applied. The previously reported paired two DOF morphing control [19] was meant to counteract adverse roll during yaw tilting. This was compensated for by the sweep-morphing wing capabilities.…”

“…The results of the converged FEA model showed a maximum planar feather expansion angle change of 46 • with a 6 N force applied to the central shaft or a prescribed 10 mm input displacement and a 45 • with a 4.4 N force or 6.6 mm prescribed displacement in the opposite direction (detailed in Section 3.1). Compared to the left-and right-hand tail planar morphing design of Murayama et al [19], symmetric planar morphing was applied. The previously reported paired two DOF morphing control [19] was meant to counteract adverse roll during yaw tilting.…”

“…Bio-inspired tail designs have been pursued in small ornithopters, however; hobbyists often use this design out of the need to maximize lift. A four-degree-of-freedom bio-inspired tail on a fixed-wing drone was evaluated in a wind tunnel by Murayama et al [19] to demonstrate its pitch, roll, and yaw characteristics under various conditions.…”

Wind Tunnel Balance Measurements of Bioinspired Tails for a Fixed Wing MAV

“…Recent research, led by Murayama et al in [15], focused on the development of a tail mechanism inspired by bird tail feathers for bio-inspired vehicles. To evaluate its aerodynamic efficiency, force and moment measurements were conducted using a sixcomponent balance in a wind tunnel, while the attitude of the tail was varied in terms of the pitch, roll, and yaw angles relative to the vehicle.…”