Physical input modelling and identification for a helicopter UAV

Approaches to helicopter UAV control often use the main and tail rotor thrusts, and the main rotor flapping angles as inputs. However, servomotors control the helicopter´s four physical inputs which are the main rotor cyclic and collective pitch, and the tail rotor collective pitch. Helicopter models which treat the physical input are generally intractable for model-based control. We propose and identify a physical input model which is algebraically simple and therefore suitable for use in control design. The proposed model includes the vehicle´s velocity to improve its accuracy.