Trajectory Tracking Control for Quadrotor UAVs based on Composite Nonsingular Terminal Sliding Mode method

This paper investigates the trajectory tracking problem of quadrotor unmanned aerial vehicles (UAVs) with consideration of both attitude and position dynamics. First of all, the trajectory tracking problem are divided into the commands tracking in position and attitude loop by introducing the virtual attitude angles command. Secondly, the high-order sliding mode observers (HSMOs) are introduced to estimate the lumped disturbances both in position and attitude loops. And then the composite nonsingular terminal sliding mode (NTSM) controllers are constructed by introducing the estimation information of HSMOs into the NTSM controller design process. Finally, the simulations based on the data of a practical UAV are carried out to verify the effectiveness of the proposed method.