Adaptive Fixed Time Nonsingular Terminal Sliding-Mode Control for Quadrotor Formation With Obstacle and Inter-Quadrotor Avoidance

In this paper, a robust and safety distributed formation control with unknown external disturbances is researched. For a multi-quadrotors system, a novel nonsingular terminal sliding mode control strategy is studied to realize the formation control with collision avoidance and inter-quadrotor avoidance. The formation controller is redesigned once the system reaches the small field of sliding surface to solve the existence of singular of quadrotor formation and realize the fixed time convergence of singularity region. Then, the position controller and attitude controller are designed to maintain formation configuration with collision avoidance and track the desired angular rate with disturbances, respectively. The global fixed time convergence of quadrotor formation is verified by Lyapunov theory with the fixed time convergence characteristic of singularity region and nonsingular region. At last, simulation results are presented to demonstrate the efficiency of the developed algorithm.