Dynamic modeling and intuitive control strategy for an "X4-flyer"

This paper describes an intuitive control strategy for a four rotors vertical take-off and landing (VTOL) remote-controlled vehicle known as the "X4-flyer". A quasi-stationary flight dynamic modeling including gyroscopic effects due to the rotors dynamics is proposed. A nonlinear controller simplifying the vehicle manipulation and insuring quasi-stationary flight conditions is developed. The approach considers that the rotor dynamics are negligible compared to the body dynamics and develops a control law based on saturating the linear dynamics for bounding the vehicle orientation and limiting it to very small values. Experimental results show the success of this approach.