Attitude Control of Quadrotor UAV Based on SMC-ADRC

In response to the issues of external disturbances and model uncertainties during the flight of quadrotor unmanned aerial vehicles (UAVs), as well as the control challenges posed by the underactuation and strong coupling of the quadrotor, a Sliding Mode Control with Active Disturbance Rejection Control (SMC-ADRC) method is proposed. An Extended State Observer (ESO) was designed to estimate model uncertainties and unmeasurable external disturbances. Sliding Mode Control (SMC) is used to replace the Nonlinear State Error Feedback(NLSEF) in ADRC, which improves the robustness and response speed of the controller. A saturation function is employed to replace the sign function typically used in traditional sliding mode controllers, ensuring the continuity of the controlled variables. Finally, simulation experiments demonstrate that SMC-ADRC can effectively improve control accuracy and disturbance rejection capability.