Publication

Abstract : We investigate the planar dynamics of aerial payload systems, in which we model the tow-cable as a geometrically exact (GE) beam and the payload as a rigid body. A GE beam incorporates large displacements, large rotations, and cross-sectional shear. Aerodynamic loads on the cable are computed on each element and then summed. Given its large mass, the towing aircraft is taken to be unaffected by the system’s motion. We derive the equations of the system and solve these using a nonlinear finite element method. We then study the effect on the system’s dynamics of cable length, payload size, downwash, and wind speed. Finally, we investigate practically relevant transient flight scenarios. We find that the flight path influences the system’s response, and minimizing motion derivatives limits payload’s motion. Our general formulation is easily extended to three-dimensions and useful for many aerial or underwater towed systems.