Quadcopter UAVs Extended States/Disturbance Observer-Based Nonlinear Robust Backstepping Control

Area of Science:

• Robotics
• Control Systems Engineering
• Aerospace Engineering

Background:

• Quadcopter unmanned aerial vehicles (UAVs) are susceptible to external disturbances affecting their stability and trajectory tracking.
• Existing control methods often struggle to provide robust performance under uncertain environmental conditions.

Purpose of the Study:

• To develop a robust trajectory tracking control algorithm for quadcopter UAVs.
• To enhance attitude stabilization and three-dimensional position tracking performance.
• To ensure system stability without precise knowledge of disturbance bounds.

Main Methods:

• Establishment of a mathematical model for a quadcopter UAV considering exogenous disturbances.
• Design of an extended state/disturbance observer (ESDO) using a general second-order model to estimate perturbations.
• Construction of a nonlinear robust controller by integrating backstepping techniques with the ESDO.

Main Results:

• The proposed controller achieves robust attitude stabilization and superior 3D position tracking.
• Robust stability of the closed-loop system is guaranteed via Lyapunov theorem, even with unknown disturbance bounds.
• Numerical simulations demonstrate significant advantages over previous control methods.

Conclusions:

• The integrated backstepping and ESDO approach provides an effective and robust solution for quadcopter UAV trajectory tracking.
• The method offers enhanced performance and stability in the presence of external disturbances.
• This control strategy is highly effective for demanding UAV applications.