Robust flight control design using incremental adaptive sliding mode control

Incremental Adaptive Control is proposed to design the control allocation for a V-Tail UAV. This approach is able to improve performance and reliability when the UAV experiences external disturbance and parametric uncertainties. In this paper, a sliding mode control (SMC) based technique is used as baseline controller to develop this incremental adaptive control. This baseline controller sets the system states always to stay and within acceptable range on the sliding surface in finite time. The adaptation law is added to observe the states from desired ones and reduce the error gradually. Incremental approach, finally is applied to the adaptive SMC which leads the controller become more robust to model uncertainty. It reduces the dependency controller from plant parameters thus the system become less sensitive. The stability of this incremental adaptive approach is proven using Lyapunov method. Simulation results demonstrate that the approach can improve flight performance when the system experience external disturbance and reduce the sensitivity of parametric uncertainty thereby making the desired state tracking can be achieved effectively.