An at-scale tailless flapping-wing hummingbird robot. I. Design, optimization, and experimental validation

Designing a hummingbird-inspired, at-scale, tail-less flapping-wing micro aerial vehicle (FWMAV) is a challenging task in order to achieve animallike flight performance under the constraints of size, weight, power, and actuation limitations. It is even more challenging to design such a vehicle with a pair of independently controlled wings equipped with a total of only two actuators. This article details a systematic solution for the design optimization and prototyping of such FWMAVs. The proposed solution covers the complete system models and analysis of wing-actuation dynamics, control authorities, body dynamics, mechanical limitations, and electrical constraints. Each subsystem, as well as the overall system, is experimentally validated. This comprehensive approach can facilitate the design of such FWMAVs with different optimization goals. To demonstrate the effectiveness of the proposed approach, in this article, we conduct three different design optimization tasks, which yield three different prototype systems: optimizing the lift-to-weight ratio, optimizing control bandwidth, and optimizing control authority. We first construct a vehicle with an optimized lift-to-weight ratio. Based on it, the other two platforms with different design optimization goals are presented for better flight performance. Flight tests were performed on each prototype to validate their flight performance and design goals. Compared to optimized control bandwidth, we demonstrate that the vehicle with optimized control authorities is significantly more capable in terms of flight performance. It shows sustained stable flight in both hovering and heavy load carrying (more than 60% of the vehicle's total weight), which is hard for the other two platforms to achieve.