Internal Model-Based Anti-Disturbances Low-Level Control for Drones Considering Actuator Dynamics

Low-level control plays a critical role in the overall flight performance of drones. Despite some progress, existing methods do not adequately consider the complex electromechanical characteristics of actuators and aerodynamic disturbances of propellers, which deteriorates low-level control performance. To tackle these issues, we propose a new nonlinear low-level controller for higher precision control. First, a high-precision low-level model that integrates the actuator dynamics and angular velocity dynamics is presented. Based on this model, a dynamic compensator is designed using the internal model method to handle aerodynamic disturbances. Next, a high-gain observer is designed to estimate the actuator states without adding new sensors, and an observer-based low-level controller is proposed through a recursive design process. Finally, the local asymptotic stability of the closed-loop system is analyzed. The effectiveness and superiority of the proposed method are validated through simulations and physical experiments.