Generic Adaptive Sliding Mode Control for a Quadrotor UAV System Subject to Severe Parametric Uncertainties and Fully Unknown External Disturbance

This paper aims to provide a generic robust controller that is able to manipulate all kinds of quadrotor unmanned aerial vehicle (UAV) systems automatically or adaptively in the presence of severe parametric uncertainties and fully unknown external disturbance. The dynamic model of the quadrotor is first obtained using Newton-Euler equations. Then, considering the underactuated and the strongly coupled characteristics of the quadrotor system, a nonlinear adaptive sliding mode control (ASMC) scheme is proposed. Meanwhile, additional adaptive laws are designed to estimate all the parameters of the quadrotor system, which in principle are difficult to be measured directly and accurately. Furthermore, to guarantee the asymptotic stability of the closed-loop system, the upper bound of the fully unknown external disturbance is estimated and adopted as the switching gain of the ASMC. Finally, simulations and experiments are carried out to illustrate the effectiveness and robustness of the proposed control scheme, where the superiority to linear quadratic control (LQR) and active disturbance rejection control (ADRC) has been demonstrated clearly.