Active Disturbance Rejection Control for a Coaxial Rotor Unmanned Aerial Vehicle

In this paper, a flight control scheme based on ADRC technology is designed and implemented for a small coaxial rotor UAV (CRUAV) under the condition of internal parameters perturbation and external nonlinear and periodic disturbance. First, the internal parameters perturbation and external nonlinear and periodic disturbances are estimated and compensated by linear extended state observer to ensure that CRUAV has good anti-jamming ability. Secondly, a cascade ADRC controller is designed for CRUAV. Using the Lyapunov theorem, the stability of the closed-loop system is demonstrated. Thirdly, in the presence of perturbation of internal parameters and external disturbances, the trajectory tracking simulation experiment of CRUAV is carried out, and compared with the PID algorithm, by which proved that the ADRC algorithm is more robust than the traditional PID algorithm. Finally, the self-built coaxial rotor UAV prototype system is used to verify the ADRC controller. The outcomes demonstrate that the coaxial rotor UAV prototype system can maintain attitude stability in the presence of external disturbances, demonstrating the viability of using the developed controller in engineering practice.