Modeling and simulation of flexible UAVs with large aspect ratio

Full non-linear equations of motion for a flexible UAV with large aspect ratio are developed. Lagrangepsilas equation and principle of virtual work are used to derive equations of motion. The structure is considered to be operating in elastic region and linear structural theory is applied. Aerodynamic loads and moments are calculated using a panel code based on vortex lattice theory capable of handling unsteady forces and moments. The developed model allows the structure to go under large deformations and considers the structural dynamics. The fully coupled equations of motion are then simplified based on the flight conditions and are represented in state-space form suitable for integration with modern control techniques. Finally, the developed model is applied to a generic UAV with large aspect ratio and the wing tip acceleration is compared to the wing tip acceleration of the rigid aircraft.