Control of variable-pitch quadrotors

The problem of control law design for a small scale quadrotor helicopter enabling both speed and pitch control is considered. The tradeoff between speed and pitch control is first investigated with reference to a linear design problem. The overall control problem is then posed on the pitch control and is formulated in terms of an outer (position) loop and an inner (attitude) one. The design of the controller for position dynamics is based on the flatness property, while attitude control is dealt with by means of an (almost) globally stabilising control law.