Active and Robust Twisting Morphing Wings With Geometric Constraints for Flying or Swimming Robots

Abstract

Typically, a twisting morphing wing of flying or swimming robots has one spanwise shaft and many ribs, the ribs can swing in their individual planes perpendicular to the shaft or the spanwise direction of the wing, showing different swing angles and different speed ratios with respect to the rotation of the shaft, thus the wing can form various degrees of spanwise twisting as the shaft rotates. While feasible solutions and mechanical implementations via gear transmission with tight geometric constraints are largely unexplored. This article considers the tight geometric constraints for such robotic twisting wing, and provides and particularly expands the analytical feasible solutions for the constraints, as well as provides mechanical implementations for active twisting of the wing that is driven by only one motor installed at the wing base, which implementations are compact with low inertia, low control complexity, and also high robustness that tolerates the deformations (e.g., bending due to load) of the shaft. The results serve as a design guidance and can be used for morphing wings of flying or swimming robots, particularly for accurately active spanwise twisting and large load transmissions to the movable parts.