An Approximate Backstepping Control Law for the Global Stabilisation of Symmetric VTOL Vehicles

In this paper we propose an approximate backstepping control law for the stabilisation of six degree of freedom symmetric VTOL vehicles. This control law results in closed-loop dynamics with a stable cascade structure. An additional innovation is to design feedback such that the interconnection term between resulting cascaded sub-systems is minimised. The proposed control law is proven to be globally, exponentially stable. Simulation results show aggressive stabilisation and the benefits of minimising the closed-loop interconnection term.