Robust control design of a quadrotor UAV based on incremental hierarchical sliding mode approach

This paper presents the design and implementation of a nonlinear control algorithm for quadrotor helicopters which have become increasingly important by virtue of their high degrees of manoeuvres ability to hover. This algorithm is based on the incremental sliding mode controller (ISMC) technique, whereby the robustness is ensured presence of unknown time-varying wind disturbances for a quadrotor. Foremost, the first-level sliding surface is described, and then one of the left variables is utilized to construct the next sliding surfaces and this process continues till the last sliding surface is constructed. In addition the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. The suggested algorithm is verified in studies in the execution of various maneuvers subject to forcible wind disturbance while performing accurate attitude and position tracking by running an extensive numerical simulation.