From studying real hummingbirds to designing hummingbird-like robots - a literature review

In this paper, the interpretation of hovering flight for hummingbirds is studied from a hummingbird morphology perspective (muscle and skeleton) including weight distribution, followed by a discussion of hovering aerodynamics. Next, by studying the scale laws, geometry similarity, and statistical analysis on wing parameters, the parametric relation between wing performances and weight is studied, followed by flapping wing micro autonomous drones (FWMADs) design. The efficiency of the designed wings based on the scaling law is verified by flying test. Material difference and methods of design are summarized. Last, the morphology of bird's tails is presented, and then the designs of tails are introduced, followed by discussion of tail performances. The results show that the tail could be predicted to apply to the stability of hovering twin-wing FWMADs. The current studies provide a simple but powerful guideline for biologists and engineers who study the morphology of hummingbirds and design FWMADs.