Parafoil Glide Slope Control Using Canopy Spoilers

Abstract

Current autonomous parafoil and payload aircraft are controlled by deflection of left and right brakes, leading to lateral-directional control. While left and right brakes can be deployed symmetrically, the main effect is to alter speed and not glide slope of the vehicle. Thus the use of left and right brakes produces lateral control but not longitudinal control of the vehicle. As a consequence, landing accuracy is reduced, especially when difficult terrain or significant atmospheric gusts are present near the landing area. Previous research has shown that improved landing accuracy can be achieved using glide slope control generated by dynamic modification of the canopy incidence angle. The work reported here considers generation of glide slope control authority for parafoil and payload aircraft using a novel approach of integrating aerodynamic spoilers into the canopy. Both an upper surface slitspoiler and a lower surface flap-spoiler are investigated. It is shown that significant glide slope control can be achieved with either device.