Robust Trajectory Tracking Control for a Quadrotor Based on a Composite Sliding Mode Control Method

This study proposes a composite sliding mode control (CSMC) method to achieve trajectory tracking control of a quadrotor aircraft with disturbances and uncertainties. As a combination of two types of sliding mode controller, the proposed composite controller is capable of solving both disturbances and input constraint problem. Firstly, the quadrotor control system is divided into a fully-actuated subsystem and an under-actuated subsystem. Secondly, a non. si. ngular fast terminal sliding mode control method is introduced for the fully-actuated subsystem to make the altitude and yaw angle errors converge to zero in a finite time. Meanwhile, an anti-windup technique is applied to compensate the effect of input saturation. In addition, a sliding mode control with fast double power reaching law is employed in under-actuated subsystem to ensure position and attitude state variables converge to their desired values. Furtheimore, the stabilities of two subsystem are analyzed and the sufficient stability conditions are derived based on Lyapunov theory. Finally, Simulation results verify the superiority and robustness of the proposed control method in presence of parameter uncertainties and input constraints.