RISE and disturbance compensation based trajectory tracking control for a quadrotor UAV without velocity measurements

This paper presents a velocity-free robust trajectory tracking control for a quadrotor unmanned aerial vehicle (UAV) with consideration of parametric uncertainties and external disturbances by effectively integrating robust integral of the sign of the error (RISE) feedback control with extended state observer (ESO). The original cascaded dynamics of quadrotor UAV is first derived in a strict form with lumped disturbances. Then, the robust RISE partial state feedback controllers with disturbance compensation are respectively synthesized in position and attitude loop, where the unmeasurable velocity states and disturbance compensation terms are estimated by ESO, the synthesized RISE control law is then accounted for attenuating the residual estimation error to achieve enhanced robustness against uncertainties. The major feature of proposed method is that fundamentally different anti-disturbance mechanisms of disturbance suppression-based RISE control and disturbance observer-based control are combined to handle the lumped disturbances simultaneously, which preserves their theoretical advantages while overcoming their performance limitations. Moreover, the proposed controller theoretically guarantees that the tracking error converges to a small neighborhood around the origin. The effectiveness and superiority of proposed control method are investigated in simulations against disturbances due to parametric uncertainties, wind gust and bounded perturbations.