Adaptive robust tracking control of quadrotor helicopter with parametric uncertainty and external disturbance

This paper proposes an adaptive robust tracking control strategy for a quadrotor helicopter with parametric uncertainties and external disturbances based on sliding mode control. The inner loop of the control strategy is concerned about the attitude and altitude control of the quadrotor helicopter, while the outer loop is employed to track the desired horizontal positions. By assuming knowledge of the bounds on external disturbances, an integral sliding mode control is designed to maintain system performance and keep it insensitive to disturbances. For parametric uncertainties (e.g., total mass and moments of inertia) of the quadrotor helicopter, an on-line adaptive scheme is proposed and incorporated into the nominal sliding mode control to deal with it. With this adaptive scheme, there is no need to know the parametric uncertainty bounds. A guaranteed transient and steady-state tracking performance can be obtained with the adaptive robust sliding mode controller. The effectiveness of the proposed control strategy is validated through a simulation on a quadrotor helicopter subject to parametric uncertainties and external disturbances.