Control of Quadrotor Using Sliding Mode Disturbance Observer and Nonlinear H∞

In this paper, a nonlinear model of the underactuated six degrees of freedom (6 DOF) quadrotor helicopter was derived based on the Newton-Euler formalism. A new nonlinear robust control strategy was proposed to solve the stabilizing and path following problems in presence of external disturbances and parametric uncertainties. The proposed control structure consist of a sliding mode control based on disturbance observer (SMDO) to track the reference trajectory together with a nonlinear H∞ controller to stabilize the rotational movements. Simulation results in the presence of aerodynamic disturbances and parametric uncertainties are presented to corroborate the effectiveness and the robustness of the proposed strategy.