Finite-time wind-rejected bipartite time-varying formation control of multiple quadrotors using hierarchical super-twisting sliding mode algorithm

This paper proposes a hierarchical super-twisting sliding mode control (ST-SMC) scheme incorporating a fixed-time extended state observer (FT-ESO) to address the bipartite time-varying formation control (BTVFC) problem of multiple quadrotors under wind disturbances. First, a coupled six-degree-of-freedom (6-DoF) dynamic model incorporating wind-induced aerodynamic effects is developed. Then, an FT-ESO is designed to estimate wind-induced disturbances. Subsequently, a hierarchical control strategy is designed: a finite-time state observer (FTSO) estimates the desired position and velocity, while an ST-SMC strategy achieves high-precision position tracking. The desired attitude angles are obtained via nonlinear dynamic inversion (NDI), and an additional ST-SMC strategy is adopted to ensure robust attitude tracking. The global finite-time convergence of the closed-loop system is rigorously proven by stability analysis. Finally, 6-DoF simulation results demonstrate the effectiveness and strong disturbance rejection capability of the proposed control framework.