The flying anemometer: Unified estimation of wind velocity from aerodynamic power and wrenches

We consider the problem of estimating the wind velocity perceived by a flying multicopter, from data acquired by onboard sensors and knowledge of its aerodynamics model only. We employ two complementary methods. The first is based on the estimation of the external wrench (force and torque) due to aerodynamics acting on the robot in flight. Wind velocity is obtained by inverting an identified model of the aerodynamic forces. The second method is based on the estimation of the propeller aerodynamic power, and provides an estimate independent of other sensors. We show how to calculate components of the wind velocity using multiple aerodynamic power measurements, when the poses between them are known. The method uses the motor current and angular velocity as measured by the electronic speed controllers, essentially using the propellers as wind sensors. Verification of the methods and model identification were done using measurements acquired during autonomous flights in a 3D wind tunnel.