On-board Downwash Speed Estimation of Drone Rotor-Based State Observer

Abstract

Drone dynamics are a ff ected by fl ight condition uncertainties, such as the surrounding structure, gust disturbance, and rotor damage, resulting in the deterioration of fl ight performance and safety. Real-time modeling of drone dynamics plays an important role in fl ight safety. In this study, the on-board measurement of downwash speed, which is an important parameter in drone dynamics, was performed using ultrasonic passing-time information. In this method, ultrasonic transmitters and receivers were arranged below the rotor, and the passing time in the downwash was estimated using an extended Kalman fi lter, which was designed for the constructed ultrasonic propagation dynamics model. It was validated that the proposed method is su ffi ciently robust to accurately estimate the downwash speed in a disturbed fl ow under a rotating rotor.