extended state observer Aerial vehicle 1 Aircraft control 1 Aircraft detection 1 Antennas 1 Backstepping 1 Backstepping control 1 Controllers 1 Disturbance observer 1 Extended state observer 1 Navigation 1 Observer-based 1 Performance 1 Position control 1 Quadcopter unmanned aerial vehicle 1 State disturbance 1 Trajectory tracking control 1 Trajectory-tracking 1 Unmanned aerial vehicles (UAV) 1 active disturbance rejection control 1 active vibration control 1 backstepping control 1 cascade active disturbance rejection control 1 disturbance observer 1 inertial actuator 1 measurement noise 1 nonlinear function filtering 1 nonlinear systems 1 quadcopter UAV 1 trajectory tracking 1