Dynamic event-triggered fractional-order super-twisting control for practical fixed-time quadrotor tracking under DoS attacks

Denial-of-service (DoS) attacks interrupt controller-to-actuator communication in quadrotor unmanned aerial vehicles (UAVs), preventing timely control updates and degrading trajectory-tracking accuracy. External disturbances and limited communication bandwidth further complicate precise tracking under such attacks. To address these problems, a dynamic event-triggered fractional-order super-twisting control strategy is proposed to achieve practical fixed-time trajectory tracking under DoS attacks. First, a fractional-order sliding surface with nonsingular dual-power feedback is designed to improve the tracking performance of the position and attitude subsystems. Subsequently, a generalized super-twisting controller is constructed to enhance disturbance rejection and alleviate chattering. Considering the limited communication bandwidth during remote control, a dynamic event-triggered mechanism (ETM) with a strictly positive threshold floor is developed to reduce unnecessary command transmissions. An acknowledgment-based retry strategy is introduced to restore command updates after communication interruptions, while the actuator retains the most recently received command during the outage. Within the prescribed operating domain, Lyapunov analysis establishes practical fixed-time stability under DoS attacks for the closed-loop system on a prescribed compact set of initial conditions. Moreover, a strictly positive lower bound on successive transmission attempts is derived to exclude Zeno behavior. Finally, numerical simulations verify the effectiveness of the proposed control strategy.