Fixed-Time Sliding Mode Control of QUAV Attitude System Based on Disturbance Observer

In this paper, the fixed-time stability of the attitude system of a quadrotor unmanned aerial vehicle (QUAV) under external time-varying disturbance is investigated. A novel disturbance observer with state dependent variables as exponents is designed to estimate time-varying perturbations. Subsequently, a fixed - time controller is engineered to achieve fixed-time convergence of the QUAV's attitude system. The efficacy of the proposed algorithm is validated through numerical simulation.