Real-Time Wind Field Estimation and Pitot Tube Calibration Using an Extended Kalman Filter

• Published in: Mathematics (Basel) Vol. 9; no. 6; p. 646
• Main Authors: Zhang, Qian, Xu, Yifan, Wang, Xueyun, Yu, Zelong, Deng, Tianyi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2021
• Subjects: Accuracy; Aircraft; Aircraft safety; Airspeed; Calibration; Computer simulation; Conversion; Extended Kalman filter; Flight control; Flight planning; Food science; Global positioning systems; GPS; Hovering flight; Phase transitions; Pitot tubes; Real time; Sensors; Time measurement; Trajectory planning; unmanned aerial vehicle; Unmanned aerial vehicles; Velocity; Vertical takeoff aircraft; Wind; wind field
• ISSN: 2227-7390; 2227-7390
• DOI: 10.3390/math9060646

The airspeed is an important feedback signal for flight control, and its measurement accuracy is related to the safety of aircraft, especially for hybrid vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAV) in the transition phase. However, offline calibration of the pitot tube cannot fully simulate the situation in real cases, and this is why online calibration after installation is necessary. In addition, the environmental wind field creates a high risk for the conversion flight of a hybrid UAV, thus real-time wind field measurement of the flight field has great significance for the flight path planning of the conversion process. In this article, an innovative method for online calibration of pitot tube and wind field estimation is proposed. After establishing the extended Kalman filter (EKF) for estimation, an analysis method is proposed to analyze the observability of EKF under different flight strategies. Then, the hovering flight is selected as the experimental flight trajectory. The laboratory computer simulation and flight experiment results validate the theory and prove that the proposed method could re-calibrate the scale factor of the pitot tube and estimate the wind field.