Impulsive Prescribed Performance Anti‐Disturbance Tracking Control for UAH Attitude System: A Low‐Complexity Method

This paper proposes a low‐complexity anti‐disturbance tracking control strategy for the attitude system of unmanned autonomous helicopter (UAH), aiming to address the issues of degraded tracking performance and system instability caused by external disturbance and discontinuous reference signal. First, a suitable time‐varying scaling function is introduced, based on which an improved prescribed‐time disturbance observer (PTDO) is constructed to rapidly estimate disturbance, ensuring that the estimation error converges to a sufficiently small bound in the prescribed time. Second, to mitigate the adverse effects of discontinuous reference signal, an appointed‐time prescribed performance function (APPF) with impulsive dynamics is proposed, from which the performance boundaries can be designed accordingly, allowing immediate redefinition of boundaries when the reference signal undergoes sudden changes. Third, a low‐complexity controller based on PTDO and prescribed performance control (PPC) is developed. It not only ensures that the attitude tracking error consistently remains within the performance envelope but also features a simplified structure that effectively reduces the analytical and computational burden in generating the control signals. Furthermore, by proving the bounded stability of all signals in the closed‐loop system via Lyapunov theory, a co‐design method for the controller and observer is presented. Finally, numerical simulations verify the effectiveness and superiority of the proposed control approach.