Reliability Oriented Fixed Time Control for Quadrotors Subject to Actuator Degradation

ABSTRACT In safety‐critical missions, actuator degradation and severe environmental disturbances pose significant operational risks to Quadrotor UAVs, complicating reliability assessment and mission safety planning. To guarantee operational safety and enhance system reliability under these uncertainty‐laden conditions, this paper develops an adaptive fixed‐time super‐twisting sliding‐mode controller (FTASTSMC) to address the coupled attitude‐position tracking problem. This strategy integrates two critical safety features: (1) a chattering‐suppressed continuous super‐twisting algorithm for mitigating actuator wear and supporting long‐term maintenance objectives and (2) an adaptive mechanism for compensating unmodeled faults without requiring a priori bounds. Theoretically, the system states are proven to converge within a fixed time independent of initial conditions. This yields a deterministic worst‐case recovery‐time budget, providing an explicit temporal safety margin for risk quantification and mission planning. Comparative benchmarking demonstrates that, compared to conventional sliding‐mode strategies, the proposed FTASTSMC significantly minimizes the risk exposure time and reduces the wear index during fault recovery. The results confirm that the proposed scheme systematically reduces the operational risk footprint of the quadrotor, offering a practical basis for safety‐margin design and extending the remaining useful life of degraded systems.