Fully Actuated System Approach Based Prescribed-Time Fault-Tolerant Formation Control for Unmanned Helicopters Under Fixed and Switching Topologies

The fault-tolerant formation control problem for unmanned helicopters (UHs) with actuator faults under fixed and switching communication topologies is investigated in this paper. Firstly, the high-order fully actuated system model of the 6-DOF UH is established, which is divided into the position outer-loop subsystem and the attitude inner-loop subsystem. Secondly, a prescribed-time disturbance observer is constructed to rapidly and accurately estimate the composite disturbances composed of external disturbances and actuator faults. Then, with the aid of the fully actuated system approach, the formation fault-tolerant controller and attitude tracking fault-tolerant controller are designed for the inner and outer loops respectively, which can guarantee the prescribed-time stability of multiple UHs under fixed and switching topologies. Finally, the simulation results are provided to demonstrate the effectiveness of the proposed control strategy.