Coaxial Tilt-Rotor UAV: Fixed-Time Control, Mixer, and Flight Test

The coaxial tilt-rotor (CTR) unmanned aerial vehicle (UAV) is a distinctive multirotor aircraft which incorporates two coaxial tilt-rotor (CTR) modules and a rear rotor, enabling it to execute diverse maneuvers and achieve high-speed forward flight. In this work, according to the specific configuration of the CTRUAV, a cascaded fixed-time (FT) control strategy and a nonlinear state-varying mixer are proposed to improve the CTRUAV's stability, transient performance, and robustness. The FT convergent property of the designed control strategy is validated and discussed by simulations. Finally, real-time experiments are implemented on a self-built CTRUAV experimental platform. The simulations and experimental results with different controllers demonstrate the effectiveness and superiority of the designed control method.