Predetermined Performance Function‐based Adaptive Fixed‐time Terminal Sliding Mode Control for a Quadrotor <scp>UAV</scp>

Abstract To enhance the trajectory tracking control performance of a quadrotor Unmanned Aerial Vehicle (QUAV) under external disturbances, this paper designs a predetermined performance‐based fixed‐time fast terminal sliding mode controller (FFTSMC). Firstly, a novel predetermined performance function (PPF) and a transformation function are constructed to convert the constrained system state error into an unconstrained error problem. Based on the transformed error, a new FFTSMC is proposed to improve the system's convergence rate. Secondly, for external disturbances, a new adaptive law is developed to estimate the upper bound of system disturbances and achieve dynamic compensation, thereby enhancing the system's anti‐interference capability. Finally, the effectiveness of the proposed control strategy is demonstrated through rigorous theoretical proofs and simulations. Simulation results show that the proposed control method achieves stable tracking of the desired trajectory and consistently constrains the error within the predetermined performance bounds, even in the presence of external disturbances and measurement noise. Compared with other control algorithms, the proposed method improves the Integrated Absolute Error (IAE) by 72% and 91.4%, and the Integrated Time Absolute Error (ITAE) by 81.1% and 91.5%.