Hierarchical Formation Control for Multi-UAV Systems: A Saturated-Input Approach

Due to the limitation of Unmanned Aerial Vehicle(UAV)'s maximum velocity/acceleration, its control input needs to satisfy the saturation constraint. In this paper, we study the formation control problem for discrete-time multi-UAV systems with input saturation constraints. A hierarchical formation control law is constructed based on the flocking behaviour of birds that follows the head bird. This control law is shown to achieve system convergence when the communication topology graph contains a spanning tree rooted at the leader UAV and each UAV is asymptotically null controllable with bounded controls. Simulation results verify the validity of the theory.