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.

Autonomous Control of Parafoils Using Upper Surface Spoilers

“…Overall, the asymmetric actuation of the upper surfaces spoilers is clearly an effective lateral control mechanism. a) Unactuated slit spoiler b) Actuated slit spoiler detail Based on the flight test results presented in [13], the spoiler configuration shown in Figure 4 will be used for autonomous testing with combined longitudinal and lateral control. The center 8 cells of the canopy are actuated.…”

“…The upper surface spoilers used for the flight tests in [13] are shown in Figure 1. On the top surface of the canopy, a spanwise slit is introduced across a number of cells in the center section of the wing.…”

“…Several spoiler configurations were tested in [13] for their effectiveness in controlling glide slope. The results for several configurations are shown in Figure 2.…”

“…The mass, geometry and aerodynamic parameters for the simulation model were set to represent the system used for flight testing in [13]. Spoiler actuation in the simulation model produces changes to the lift and drag…”

“…The current work seeks to apply the control logic used for autonomous flight with glide slope control to the novel parafoil control mechanism of upper surface bleed air actuation. This control mechanism vents internal air through the upper surface of the canopy to create an aerodynamic spoiler and has been shown to generate effective turn rate and glide slope control of parafoil canopies in flight test [13].…”