Modelling and Lq-Backstepping Control for a Quadrotor

Abstract

Thanks to significant advances during the last decades in the miniaturized robotic area, many Unmanned Aerial Vehicle (UAV) projects were launched. Among them, the QuadriXflyer is an UAV quadrotor designed to evolve autonomously between waypoints given by an operator before flight. In this paper, we propose a modelling and a new hybrid control approach for the QuadriXflyer; a controller integrating the advantages of a Linear Quadratic (LQ) and those of a backstepping approach allowing to compensate the nonlinearities of the system. With this new approach, the gravity will be compensated directly without time delay. Robustness of the controller is then studied to ensure the stability of the quadrotor to exogenous (wind for example) and internal (noise on measurements, uncertainties on the inertia for example) perturbations.