Disturbance observer-based backstepping control for quadrotor UAV manipulator attitude system

In this work, we approach high-precision attitude control problem of UAV manipulators in presence of external disturbances. A disturbance observer is exploited to estimate the disturbance, meanwhile we used the estimated result as a feed-forward compensation. A backstepping controller is employed to stabilize the UAV attitude by feedback. The mathematical model of UAV manipulator is constructed by combining the UAV base and the equipped robotic arm together. Furthermore, to relieve the influence of sensor noise, we fused a tracking differentiator into the whole system. The constructed method is validated in realistic simulations, where we executed UAV manipulator hovering flight with varying external disturbances.