Avian-Inspired Morphing Wing Coverings: A Multi-Objective Approach Integrating Feather Analogues

Abstract

This paper discusses the development of morphing covering solutions for a Biologically Inspired Robotic Bird (BIRB) wing concept, and proposes various types of low actuation energy morphing solutions that providing coverage for the leading and trailing edges. The BIRB wing concept revolves around a two-degree-of-freedom, bioinspired, tendon-actuated internal skeleton structure with bioinspired morphing covers capable of span extension and in-plane sweep morphing. Due to the complex changes in shape such a wing can undergo, as it is unlikely that a single morphing strategy will suffice. The form of morphing is highly dependent on the BIRB skeleton, actuation, and structural and aerodynamic boundary conditions. This paper also introduces solutions to the identified forms of morphing, which serve as functional analogs of the natural flier, including ultra-light feather-like structures that are made using muti-material additive manufacturing. This includes primary feather analogues that are mounted within a 3D demonstrator. This paper also introduces a low fidelity analytical method capable of determining the optimal feather shape and deployment tendon mounting geometry for various scenarios. Using this tool has shown that determining the optimal parameters of tendon mounting position and feather width result in an increase of allowable change in planform area over a sweep of ±25◦ from ∼5.4% to ∼34.0%.