Robust H∞ Control Synthesis of a Biomimetic Flapping Wing UAV Operating in Gusty Environment

The Unmanned Aerial Vehicles (UAVs) generally execute their missions in atmospheric boundary layer and this region is highly turbulent which drastically degrades UAVs stability. Drawing inspiration from nature for the solution, it is revealed that natural birds utilize covert feathers to tackle gusts and turbulence. This paper presents design of an active biomimetic Gust Alleviation System (GAS) augmented with robust $H_{\infty }$ controller for a flapping wing UAV (FUAV) replicating bird’s covert feathers. Reduced order model of the proposed design is computed using bond graph modelling method. Stability analysis is performed to study internal dynamics of the proposed design. A comparison is made between the proposed $H_{\infty }$ controller-augmented GAS and Linear quadratic regulator (LQR) controller-based GAS in response to external gust disturbances. The $H_{\infty }$ controller augmented GAS design demonstrate more robust behavior of the FUAV compared to LQR based design and successfully alleviates gusts up to 50%. Finally, consistency between the obtained results and literature data confirms the validity of offered $H_{\infty }$ controller.