Accurate target tracking control of two-axis gimbal system of UAV under impact disturbance

This paper proposes an adaptive finite-time control strategy with a switching-gain disturbance observer (AFTC-SGDO) for high-performance target tracking of UAV gimbal systems. A complete gimbal target tracking system is established, covering system architecture, coordinate frame formulation, dynamic modeling, controller implementation, and experimental validation on a real-world prototype. A general dynamic modeling framework based on screw theory and the Kane method is developed, in which the influence of carrier motion on gimbal dynamics is explicitly incorporated to improve modeling accuracy. To enhance tracking performance under parametric uncertainties and impact disturbances, the AFTC-SGDO strategy uses estimation errors to adaptively handle time-varying parameters and instantaneous switching gains to suppress impact disturbances. A hexarotor UAV equipped with a two-axis gimbal is developed as an experimental prototype, and experimental results verify the effectiveness of the proposed method compared with conventional approaches.