Fault-Tolerant Containment Control of Multiple Unmanned Aerial Vehicles Based on Distributed Sliding-Mode Observer

This paper investigates the distributed fault-tolerant containment control (FTCC) of multiple unmanned aerial vehicles (multi-UAVs) when a subset of multi-UAVs is encountered by actuator faults and input saturation. The topology involving multiple follower UAVs and leader UAVs is an undirected, fixed communication network and only a subset of follower UAVs has access to the leader UAVs. By the combination of graph theory and sliding-mode observer (SMO), the desired reference of each follower is first estimated in a distributed manner. Then, by utilizing the estimated knowledge, a set of distributed control laws is iteratively designed to steer follower UAVs into the convex hull spanned by the leader UAVs. In the distributed control scheme, disturbance observer (DO) technique is used to estimate unknown lumped uncertainty including external disturbances and actuator faults. An auxiliary dynamic system is constructed to compensate the input saturation. Moreover, to eliminate the “explosion of complexity” in traditional backstepping architecture, high-gain observer (HGO) technique is integrated into the backstepping architecture to estimate the virtual control signals and their first derivatives. Furthermore, by using graph theory and Lyapunov-based approach, it is shown that the distributed fault-tolerant containment controller can guarantee all follower UAVs to converge into the convex hull spanned by all leader UAVs. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed distributed control scheme.