Integral LQR Robust Control for a Hexarotor-UAV Modeled As a qLPV System

This paper presents a model quasi-linear parameter varying (qLPV) and an integral Linear Quadratic Regulator (LQR) controller for an unmanned aerial vehicle type hexarotor. The qLPV model is derived using the nonlinear sector approach, which can accurately represent the hexarotor nonlinear model under bounded nonlinear terms. Meanwhile, the goal of the controller is to achieve trajectory tracking despite disturbances caused by residual rotor speeds and wind disturbances. Trajectory tracking is accomplished by using an integrator comparator block which is divided into three subsystems governed by rotational, altitude and position dynamics. To guarantee robustness against disturbances and tracking error, a H∞ performance criterion is considered. The stability condition and robust performance are formulated using the Lyapunov quadratic function, with sufficient conditions provided by linear matrix inequalities (LMIs). Finally, numerical simulations of the proposed method are illustrated using the hexarotor model.