Robust attitude tracking control of hexarotor MAVs using plug-in gain scheduling robust compensator technique

This paper proposes a robust attitude tracking control scheme for hexarotor micro aerial vehicles (MAVs) under the effects of uncertainties (equivalent disturbances) which consist of external disturbances, nonlinear dynamics, coupling, and parametric uncertainties. The proposed scheme is easy to be implemented compared to other robust controller techniques since it consists of a nominal controller and a plug-in gain scheduling robust compensator only for pitch, roll, and yaw subsystems. The nominal controller is based on cascade PID (P, I, D denote for proportional, integral, and derivative term, respectively) control approach. A plug-in gain scheduling robust compensator is added in order to improve the attitude tracking performance due to the presence of uncertainties. The simulation results prove the attitude tracking errors are bounded in specified boundaries and demonstrate the robustness of the proposed controller and thus suitable for outdoor flight condition.