Robust global stabilization of the VTOL aircraft based on finite-time fast terminal sliding mode control

Stabilization and trajectory tracking of the vertical takeoff and landing (VTOL) aircraft are challenging problems which have been extensively investigated over the past years. This paper focuses on the robust stabilization problem of the VTOL aircraft. Firstly, by using a nonlinear global transformation, the original system is decomposed into two coupling sub-systems; then, a new finite-time fast terminal sliding mode manifold is designed. More specifically, the new finite-time fast terminal sliding mode manifold exhibits not only fast convergence rate, but also finite convergence time for any initial value; as a result, based on the designed finite-time fast terminal sliding mode manifold, one of the two sub-systems can converge to the equilibrium point in a finite time with high speed after being transformed, and then the other one is asymptotically stable, which avoids constructing the Lyapunov functions. Simulation results demonstrate the effectiveness of the proposed control strategy.