Helicopter Trajectory Optimization after Aerial Slung Load Release

The intention of this paper is to provide the pilot with optimal control time history for the stabilization of a helicopter after releasing the slung load in an aerial delivery mission. A model with 31 degrees of freedom (31-DOF) has been developed and validated for a helicopter with a slung load system, from which the reduced 6-DOF rigid body helicopter model is used to generate trajectory optimization results. Investigations have been carried out on the effects of different configurations of the objective function and different assignments of weight coefficients on optimization results to determine the most appropriate objective function. The final result complies with the conclusion that the pilot should mainly decrease the collective control and adjust the longitudinal control to stabilize the helicopter after load release, while the lateral control and pedal control can be left to the control system because of their small amplitudes, and the manipulations are more aggressive as the load weight increases.