Practically Predefined-Time Adaptive Attitude Control for QUAV With Stochastic Disturbances and Input Saturation: Theory and Experiment

This article investigates the practically predefined-time attitude control problem for a quadrotor unmanned aerial vehicle (QUAV). First, a novel attitude dynamics model is developed to incorporate both input saturation and stochastic disturbances. Unlike conventional piecewise nonlinear methods or smooth saturation approximations, an adaptive auxiliary system is proposed to directly compensate for saturation effects. Furthermore, an adaptive fuzzy control scheme is designed to achieve accurate attitude tracking with enhanced robustness. The resulting controller ensures that the attitude tracking errors converge to a small neighborhood of the origin within a predefined time, where the settling time bound can be prescribed by the user independent of initial conditions. Finally, comparative simulations and experiments on a three-degrees-of-freedom (DoF) QUAV platform validate the effectiveness and practicality of the proposed approach.