Developing an Effective Control System for VTOL UAVs in Adverse Winds

A valuable new resource being developed for today's soldiers are small ducted-fan VTOL UAVs. Although beneficial in many ways, a major operational problem of ducted fan vehicles is disturbance rejection when flying in turbulent or gusty winds. Transversemomentum drag and maintaining vehicle trim over a large speed range present significant problems for the vehicle control system. Phase I testing of various new and innovative auxiliary control effectors for ducted-fan vehicles has been encouraging. Windtunnel tests using a powered ducted-fan VTOL UAV model have demonstrated that these auxiliary control devices can change the pitching moment characteristics of the vehicle, and were particularly effective in the presence of a longitudinal crosswind orgust.In collaboration with Honeywell and AVID LLC, a Phase II work plan combining experiments and modeling of the vehicle and control systems has been developed. The objective goal of the project is to demonstrate an improved control system during flight teston a technically mature ducted-fan VTOL UAV. An optional plan is presented to demonstrate improved control in a wind tunnel environment. Either test plan will demonstrate a vehicle and control system with improved maneuverability and handling qualities ingusts. Research to improving the control system design will lead to VTOL UAVs with improved handling and more mission capability. Some future mission scenarios, such as the