Enhancing Longitudinal Flight Stability of Electric-powered Micro Unmanned Aerial Vehicles Using Fuzzy Proportional-integral-derivative Control

Electric-powered micro unmanned aerial vehicles (UAVs) have been applied in a wide range of defense and civilian applications given their flexibility, portability, and versatility. However, they are highly susceptible to wind, which can compromise control stability. This study formulated a system that makes elevator control, pitch, and roll adjustments for enhanced longitudinal flight stability in UAVs. First, the basic aerodynamic coefficients of the UAV are calculated using a digital airborne tactical communications system. Subsequently, the longitudinal motion state-space equations of the UAV are used to derive the transfer function for the pitch angle θ and horizontal stabilizer δE. Simulink was used to compare the effects of traditional proportional-integral-derivative (PID) and fuzzy PID controllers on the longitudinal flight stability of the UAV, identifying the optimal PID values. Finally, actual flight tests confirmed that fuzzy PID significantly improves the longitudinal flight stability of the UAV.