Research on the attitude control of quad-rotor UAV based on active disturbance rejection control

Aiming at quad-rotor UAV's characteristics of under-actuated, strongly coupled, nonlinear, parameter uncertainty and un-modeled disturbance, two types of active disturbance rejection control (ADRC) strategies are presented in order to increase aircraft's attitude control quality. ADRC technology is a kind of control technology which is independent of the precise model of the system, and can estimate and compensate the system's disturbance in real time. The structure and the typical algorithm of ADRC technique are described in detail, including tracking differentiator, extended state observer and state error feedback. After parameter tuning, simulations were carried out based on Simulink. Compared with a classical cascade PID control, simulation results show that linear active disturbance rejection control has better control quality and anti-disturbance performance.