CLF based design for attitude control of VTOL-UAVs: An inverse optimal control approach

This paper presents the development of a quaternion-based nonlinear control for the attitude stabilization of VTOL-UAVs. Firstly, it is proved the existence of a Control Lyapunov Function (CLF). Unlike some previously proposed schemes, the aim of this paper is to propose an optimal control using the relationship between Sontag´s Formula and optimal control problem. The control law ensures the asymptotic stability of the closed-loop system to the desired attitude. The approach is validated in real-time using a quadrotor mini-helicopter.