Abstract:Aiming at the vulnerability of multi-rotors drones to various external disturbances during flight, an active disturbance rejection control (ADRC) system was designed for a rotor control system of composite wing unmanned aerial vehicle (UAV) as the research object. Firstly, the kinematics and dynamics models of the multi-rotor drone system were established. Secondly, the characteristics of the ADRC algorithm were studied, and position and attitude controllers were designed in combination with the drone model. The extended state observer (ESO) was improved by introducing a more accurate dynamic model, which enhanced the disturbance observation speed and estimation accuracy. At the same time, the order of the extended state observer was reduced, and the simplicity of controller parameter tuning was improved. Furthermore, based on the six-degree-of-freedom force and moment balance equation, a control allocation model was built for the research object. Finally, Matlab/Simulink was used to complete the simulation model design and parameter adjustment. Internal gravity disturbance and external wind disturbance were added to the control targets. The simulation results showed that the controller designed could not only estimate and compensate for the internal and external disturbances of the system, but also had strong anti-interference ability, which could ensure that the drone reached the target position quickly and smoothly from the initial point, and maintained stable hovering. The steady-state error of attitude control was within 0.05°.