Modeling, Simulation and Control of a Bio-Inspired Electromechanical Feather for Gust Mitigation in Flapping Wing UAV

There is an increased requirement of bringing unmanned aircrafts into operational environments full of obstacles, including canyons, tall buildings, beneath forest canopies and valleys, all of which present navigation problems due to large scale turbulence. To address this issue, natural counterparts have been studied in depth. Through active and passive flow mechanism over their wings, wing morphing and deflection of covert feathers, birds attain stability in turbulent airflows. This paper presents a new bio-inspired concept whose aim is to enhance aircraft stability and maneuverability during turbulent flight. The research includes covert feathers inspired novel Gust Mitigation System (GMS) for flapping wing UAV (FUAV), which senses the forces being experienced during flight in turbulence and actuates to alleviate them. GMS comprises of electromechanical (EM) feather modules containing piezoelectric elements that act as sensors, actuators, and load-bearing members. We start by presenting the basic design of EM feather module along-with the block diagram. Afterwards, we perform modeling and simulation of EM feather module with detailed analytical understanding using bond graph modeling approach. Furthermore, state space equations are computed to analyze model internal dynamics and responses. Finally the model is synthesized with LQR controller to achieve close mimicry of natural counterparts. The proposed design successfully marks an initial step towards research into bio-inspired active gust mitigation systems for flapping wing UAVs.