Fast Fixed-Time-Synchronized Time-Varying Formation Tracking Control of Quadrotor UAVs Under External Disturbances

This paper investigates the problem of formation tracking control for quadrotor unmanned aerial vehicles (UAVs) subject to external disturbances. We propose a fast fixed-time-synchronized (FFTS) time-varying formation tracking (TVFT) control framework for quadrotor UAVs. Firstly, for each individual UAV, we design an FFTS disturbance observer compatible with the time-synchronized (TS) stabilization framework for the position loop. Secondly, we develop an FFTS formation controller to achieve synchronous convergence of all position components across the UAVs. Furthermore, considering the inherent multi-loop coupling characteristics of the quadrotor system, the proposed observer and controller are applied synchronously to the attitude loop. Compared with existing FT methods, both the designed observers and controllers yield a less conservative and more practical upper bound for convergence time. Finally, simulation results conducted with a three-UAV formation validate the effectiveness and superiority of the proposed control method.