Formation control of multiple VTOL UAVs with global stability subject to switching networks

This article investigates the problem of distributed formation control for multiple vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) under a switching network with uniform joint connectivity condition. VTOL UAV, as a representative UAV, combines the VTOL capabilities of rotary-wing aircraft with the forward flight capabilities of fixed-wing aircraft. On the one hand, a novel distributed observer is developed for each VTOL UAV to asymptotically acquire the leader’s desired information. On the other hand, considering the underactuated nature of VTOL UAVs, a hierarchical framework is introduced to achieve position tracking of the desired observation positions and attitude tracking of the commanded attitudes. Compared to existing findings, a notable feature of this study is the allowance for a directed and switching communication network. Specifically, the switching network only requires joint connectivity. Additionally, the introduction of hyperbolic tangent functions ensures the boundedness of control inputs, further guarantees the global asymptotic stability of the entire closed-loop system. Simulation results validate the effectiveness of the algorithm.