Abstract
This paper proposes a robust position control scheme for a quadrotor UAV system under uncertainties. The proposed control algorithms combine integral sliding mode and backstepping sliding mode controllers in a double-loop control structure (i.e., inner-outer loop control). The design of the proposed controller is divided into two subcontrollers, namely, attitude and position controllers for the quadrotor. In this work, a nonsimplified six-degree-of-freedom quadrotor model is first established in the presence of disturbances. Afterward, we develop a robust backstepping sliding mode controller for the attitude control of the quadrotor. Next, a robust integral sliding mode controller is designed for the outer loop of the quadrotor to ensure the position trajectory tracking capability in the presence of disturbances. The stability and performance of the quadrotor is thoroughly investigated using Lyapunov stability analysis. Numerical simulations demonstrate the effectiveness of the developed solutions for a quadrotor.