Multi-body bond graph modeling and simulation of a bio-inspired gust mitigating flapping wing UAV

Abstract

The small size of Unmanned Aerial Vehicles (UAVs) incurs many challenges, including concerns of flight stability during turbulence. To address this issue, birds as their natural counterparts have been studied in depth. This paper presents a biologically inspired Gust Mitigation System (GMS) for a flapping wing UAV (FUAV), inspired by the covert feathers of birds. The GMS uses electromechanical (EM) covert feathers that sense the incoming gust and mitigate it through deflection of these feathers. A multibody dynamic model of gust mitigating FUAV is developed by appending models of the subsystems including rigid body, propulsion system, flapping mechanism, and GMS installed to the wings, by using a bond graph modeling approach. The dynamic wing flexibility is modeled with a Euler-Bernoulli beam for realism. The simulation results show that wing flexibility enhances aerodynamic efficiency, and moreover, the performance of the proposed GMS for flexible wings is better than that of rigid wings during gusty airflows. A good agreement between experimental results with these simulations validates the proposed design as well as accuracy of the developed model.

Keywords

• flapping wing uav
• turbulence
• bio-inspiration
• gust mitigation system
• bond graph modeling
• simulation