Optimal-power Configurations for Hover Solutions in Mono-spinners

TL;DR

This paper investigates power-efficient configurations for mono-spinner UAVs, demonstrating how aerodynamic design and rotor positioning can optimize energy use during hover and trajectory tracking.

Contribution

It provides a detailed dynamic model and identifies optimal aerodynamic and geometric configurations for energy-efficient mono-spinner UAVs.

Findings

Symmetric configuration enables in-place hover.

Asymmetric configuration allows 3D trajectory tracking.

Tilting the rotor reduces power consumption without losing stability.

Abstract

Rotary-wing flying machines draw attention within the UAV community for their in-place hovering capability, and recently, holonomic motion over fixed-wings. In this paper, we investigate about the power-optimality in a mono-spinner, i.e., a class of rotary-wing UAVs with one rotor only, whose main body has a streamlined shape for producing additional lift when counter-spinning the rotor. We provide a detailed dynamic model of our mono-spinner. Two configurations are studied: (1) a symmetric configuration, in which the rotor is aligned with the fuselage's COM, and (2) an asymmetric configuration, in which the rotor is located with an offset from the fuselage's COM. While the former can generate an in-place hovering flight condition, the latter can achieve trajectory tracking in 3D space by resolving the yaw and precession rates. Furthermore, it is shown that by introducing a tilting angle between the rotor and the fuselage, within the asymmetric design, one can further minimize the power consumption without compromising the overall stability. It is shown that an energy optimal solution can be achieved through the proper aerodynamic design of the mono-spinner for the first time.