Leader–follower formation control for multiple VTOL UAVs with time-varying fault-tolerant actuators

This paper mainly studies the leader follower formation control problem of multiple vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) under time-varying actuator faults. A hierarchical control strategy is proposed for the underactuated characteristics of VTOL UAVs. Based on Lyapunov stability theory, an adaptive fault-tolerant control scheme for the outer position loop was established to achieve tracking of the target position. A fault-tolerant control strategy for adaptive inner attitude loop was designed using Nussbaum function, achieving tracking of instruction attitude. On the premise of ensuring that the inner loop can quickly track the outer loop, the stability of the entire closed-loop system has been successfully achieved. The simulation results validated the proposed theoretical results.