Abstract
The purpose of this paper is to obtain the optimal helicopter flight trajectories for reducing ground noise in the landing approach and to conduct flight experiments to confirm the effectiveness of the optimal solutions. We first build a noise model, and then define optimal control problems in order to minimize the noise levels measured at points on the ground surface for some flight constraints. The obtained optimal flights avoid the flight path angle that generates a great deal of noise and skirt the measurement points; these optimal flights are different from the conventional flight. Finally, we verify the validity of the optimal flight patterns by means of flight experiments with an experimental JAXA (Japan Aerospace Exploration Agency) helicopter. The actual flights following the optimal flights also result in noise reduction, and as a result, the study proves the effectiveness of the optimization.
