Adaptive dual fuzzy PID control method for longitudinal attitude control of tail-sitter UAV

Abstract

A variable universe fractal dual fuzzy PID controller is designed to solve the interference problems caused by the changes of airspeed and aerodynamic parameters during the transition from vertical flight to horizontal flight of tail-sitter UAV. By taking error, error change and airspeed as inputs, the controller can constantly stabilizes the system according to the changes of system error and flight status. High control accuracy is achieved and less fuzzy rules are needed due to the self-tuning of the universe. In order to improve the dynamic performance of the system, a normalized acceleration parameter is designed as fractal factor to reflect the response speed of the system. The simulation and experimental results reveal that the controller not only improves the dynamic performance and control precision of the system, but also has Strong adaptive ability to the changes of system error and flight status.