Adaptive fuzzy backstepping control for trajectory tracking of unmanned aerial quadrotor

This paper presents an adaptive fuzzy control strategy to solve the problem of trajectory tracking for quadrotor unmanned aerial vehicle in the presence of model parameters uncertainties and external disturbances. A fuzzy system is employed to approximate directly a model based control law developed using backstepping techniques. The adaptive laws for tuning the adjustable parameters of the fuzzy system are derived based on the Lyapunov theorem. The stability analysis of the designed adaptive fuzzy backstepping controller (AFBC) is shown by the Lyapunov theory. The proposed controller yields asymptotic tracking, robustness in the presence of external disturbances affecting the six degrees of freedom, and parameters uncertainties. It is proved that all signals in the closed-loop system are semiglobally uniformly ultimately bounded, and the tracking error converge to a small neighborhood of the origin. Numerical simulation results are provided to illustrate the good tracking performances of the proposed adaptive control approach.