Robust Attitude Controller for Uncertain Hexarotor Micro Aerial Vehicles (MAVs)

This paper proposes a practical robust attitude controller for uncertain hexarotor micro aerial vehicles (MAVs). The proposed robust controller consists of a nominal linear time-invariant controller and a robust compensator for pitch, roll, and yaw subsystems. The nominal controller is an inner-outer loop structure of PI+ PID (proportional-integral plus proportional-integral-derivative) control method to achieve the desired tracking of the nominal system, whilst the robust compensator is added to restrain the influence of the uncertainties (equivalent disturbances) which contain parametric uncertainties, coupling, nonlinear dynamics, and external disturbances. The real-time experimental results on the hexarotor demonstrate the effectiveness of the proposed controller in real flight condition and finally, the attitude tracking errors are proven to be ultimately bounded with specified boundaries.