Robust attitude trajectory tracking control for a quadrotor under external disturbance

Attitude stability plays an important role in quadrotor aircraft. However, it is difficult to design a robust controller to precisely track a desired attitude trajectory in the presence of external disturbance. To address this problem, a nonlinear disturbance estimator with finite-time convergence is proposed to estimate external disturbance. Then, a dynamic surface control scheme based on the disturbance estimator is developed. Therefore, the compensation for external disturbance can be achieved in the designed controller. Furthermore, the L ∞ performance of transient attitude tracking error is achieved by analyzing solution of Lyapunov function. The finite-time convergence of disturbance estimation error and the asymptotical convergence of attitude tracking error of closed-loop system are rigorously proved. Finally, the numerical simulations are carried out to demonstrate the effectiveness of the developed disturbance estimator and control scheme.