Distributed Observer-Based Formation-Fencing Control for Multi-Autonomous Aerial Vehicles

This paper investigates the problem of distributed observer-based adaptive formation-fencing control for multi-unmanned aerial vehicles (UAVs) subject to parametric uncertainties, external disturbances and input saturation. For each following UAV, a novel fixed-time distributed observer is designed to estimate the time-varying state trajectory of the leader UAV within a directed topology. To effectively hunt down a target, we focus on transition from formation control to fencing control for a swarm of UAVs. A novel continuous switching function is proposed to accomplish this transition. Disturbance observers are leveraged to estimate external disturbances to tackle wind effects on the UAVs. Unmodeled dynamics are approximated by a fuzzy logic system. Then, by utilizing the Lyapunov stability theory, it is proven that the formation tracking errors converge to the small neighborhoods of the origin. Thereafter, utilizing the designed control input signals from the position subsystem, an adaptive fuzzy control method is proposed to bring stability to the attitude subsystem. Finally, simulation results are offered to demonstrate the theoretical results.