Geometric Attitude and Position Control of a Quadrotor in Wind

This paper addresses flight stability and performance in wind of a quadrotor equipped with custom flow probes that measure the wind velocity. Wind-velocity measurements are used in the attitude and position control through the use of principled models that estimate the aerodynamic forces and moments. The aerodynamic moment is caused primarily by propeller blade flapping, whereas the aerodynamic force includes the induced drag from the rotors and drag over the body. A feedback-linearization controller prescribes inputs based on the aerodynamic models and quadrotor kinematics, which are developed on the special Euclidean group. The controller also addresses the thrust saturation using a variable-gain algorithm. Simulated and experimental results highlight the benefits of flow feedback and the variable-gain algorithm for the inner- and outer-loop control of attitude and position, respectively.