Trajectory Tracking and Formation Control of Quadrotor UAVs based on non- singular terminal super twisting sliding mode

Aiming at the problem that the trajectory tracking and formation flight of quadrotor unmanned aerial vehicles (UAVs) are vulnerable to complex and variable disturbances, this paper proposes a position and attitude tracking trajectory controller is designed for quadrotor UAVs in the formation, and a super twisting sliding mode controller is designed for the formation control. First, combining the advantageous characteristics of the non-singular terminal sliding mode and the super twisting sliding mode, a non-singular terminal super twisting sliding mode controller is designed for the position and attitude control of the leader and follower in the formation. Meanwhile, in order to enhance the anti-disturbance performance of the UAV, a finite-time disturbance observer is respectively designed on the position loop and attitude loop of the quadrotor UAV to estimate the disturbances, and the estimation is used to compensate the controller. Secondly, The UAV formation adopts the pilot-follower formation control scheme. Considering the formation flight at the same altitude, the position relationship model between the leader and the follower is constructed. Then, based on the position relationship model, the formation controller is designed based on super twisting sliding mode scheme to complete the formation control. Meanwhile, the stability of the designed control scheme is proved by using Lyapunov and the finite-time Lemma. The simulation results show that the proposed control scheme in this paper can improve the trajectory tracking accuracy of the quadrotor UAV, and enhance the stability and dynamic response speed of formation flight.