Extended state observer based finite-time fault-tolerant formation control for multi-UAVs

This paper is focused on the finite-time formation control problem for multi-UAVs, considering actuator faults and unmeasurable states. In this paper, an active disturbance rejection control strategy is designed in the inner-loop and outer-loop systems of UAVs. Extended state observers are designed to estimate the lumped uncertainties in the system incorporating parametric uncertainties, external disturbances, and actuator faults. By implementing the observer, the controller is adjusted online in real time, and the underlying dynamical system's states are accurately estimated. A shift function is introduced to the formation control to adapt to formation contraction or dispersion requirements in pursuit or reconnaissance missions, which realizes formation distance maneuver control at a set time. Additionally, the designed finite-time control laws enhance the system's transient response. Finally, based on the finite-time Lyapunov stability method, it is demonstrated that all signals of the system are bounded and the formation errors can converge to a small neighborhood around the origin in finite time. Simulation results illustrate the effectiveness of the proposed strategy.