Modelling and Identification of a RUAV

Modelling a linear mathematical model of a radio controlled (RC) helicopter in hover is the main goal of this thesis. The thesis introduces a general description about how RC-helicopters work and different phenomenons that effect the behaviour of a RC-helicopter. These phenomenons play an important role in the modelling part. The model equations of the RC-helicopter are computed by deriving mathematical descriptions of different helicopter characteristics. The flapping motion of the main rotor and the flybar are modelled since they play major role in describing helicopter dynamics. The model is linearised by using stability and control derivatives and a model structure is presented. The method describes how the external forces and moments in the rigid body equations of motion can be expressed as continuous functions of the model states and inputs. The model is divided into multiple sub-models that describe the different dynamics of the RUAV. The prarameters of the model are estimated using system identification methods. The prediction error method proved itself successful and the achieved models can accurately estimate the pitch, roll and yaw rate of the helicopter. These models could be used for further development of control designs