Airspeed Identification of Stratospheric Airships

Stratospheric airships fly in a thin atmosphere where common airspeed measurement methods are ineffective. The airspeed is closely related to the aerodynamic drag and propeller propulsion parameters, and the airspeed can be identified according to the aerodynamic drag and propeller aerodynamic performance equations. Firstly, according to the thrust-drag balance, the principle and the identification method are given to estimate the airspeed. Secondly, according to the connection between the propeller power and the airspeed, the principle and identification method of estimating the forward airspeed of the body axis are given. The error transfer boundaries of the two methods are analyzed. The validity of the airspeed identification method is verified by numerical simulation and flight test data analysis. The results of this paper can provide reference for the overall design and flight control of the airship.