A Review of Flapping Mechanisms for Avian-Inspired Flapping-Wing Air Vehicles

Abstract

This study focuses on the flapping mechanisms found in recently developed biometric flapping-wing air vehicles (FWAVs). FWAVs mimic the flight characteristics of flying animals, providing advantages such as maneuverability, inconspicuousness, and excellent flight efficiency in the low Reynolds number region. The flapping mechanism is a critical part of determining the aerodynamic performance of an FWAV since it is directly related to the wing motion. In this study, the flight characteristics of birds and bats are introduced, the incorporation of these flight characteristics into the development of FWAVs is elucidated, and the utilization of these flight characteristics in the development of FWAVs is explained. Next, the classification and analysis of flapping mechanisms are conducted based on wing motion and the strategy for improving aerodynamic performance. Lastly, the current research gap is elucidated, and potential future directions for further research are proposed. This review can serve as a guide during the early development stage of FWAVs.

Study on the Glider Soaring Strategy in Random Location Thermal Updraft via Reinforcement Learning

“…In recent years, the long-endurance flight mode of soaring birds using wind energy has attracted the attention of researchers [2][3][4][5]. Different types of birds have different flight strategies, and some large birds do not fly mainly by flapping, but by intermittent flapping or soaring [6]. By constantly searching for and utilizing thermal updrafts, these birds can fly for long periods without even flapping their wings.…”

A Retrospective of Project Robo Raven: Developing New Capabilities for Enhancing the Performance of Flapping Wing Aerial Vehicles

“…Robo Raven's wings also lack the fine control achieved by birds through the use of feathers, and the twist dynamics are a passive function of the forces imposed on them as opposed to a system with multiple degrees of freedom, as in birds. Future directions of research include increasing controllable degrees of freedom for wings to support a richer variety of flight modes and the use of feathers to control aerodynamics characteristics of wings [64]. New advances in actuator technology also need to be explored to achieve these capabilities.…”