Identification of directional runway dynamics for an experimental UAV

The knowledge of the ground directional behavior of an UAV during the ground phase is crucial in order to develop an automatic take-off and landing control system. During such development program, it is very common to use prototypes. These prototypes have specifics components and mostly of the performance characteristics of these components are unknown. This paper deals with the identification of the ground dynamics of a nose wheel tricycle landing gear by using real UAV runway tests data. A simplified mathematical model is proposed for identification by using Output Error Method with minimization of the cost function by Levenberg-Marquartd. The identification results enable development of ground steering laws.