Adaptive Practical Predefined-Time Formation Tracking for Multiple Quadrotors With Time-Varying Parameters

This paper proposes a distributed leaderless adaptive predefined-time formation control scheme for multiple quadrotor UAV systems subject to time-varying aerodynamic uncertainties and external disturbances. The control framework addresses both attitude stabilization and position tracking in a unified manner. The main contributions are fourfold: firstly, a novel adaptive mechanism is developed to handle parametric uncertainties arising from time-varying air drag coefficients and aerodynamic parameters. Secondly, a continuous high-frequency learning-based robust controller is designed to compensate for external disturbances while eliminating chattering phenomena inherent in conventional sliding mode approaches. Thirdly, a distributed predefined-time control protocol is constructed to achieve leaderless formation tracking without requiring global state information. Fourthly, rigorous theoretical analysis guarantees that both attitude and position tracking errors converge to a designer-specified residual set within a predefined time, whose upper bound is explicitly determined a priori independently of initial conditions. Finally, simulation results are provided to verify the theoretical results and demonstrate superior performance compared with existing methods.