Flight Testing Full Conversion of a 40-kg-Class Tilt-Duct Unmanned Aerial Vehicle

Abstract The development of a tilt-duct UAV is presented herein. In order to develop a tilt-duct UAV, the power-train characteristics of the tilt-duct vehicles during helicopter-to-airplane conversion are investigated. The full-scale model reflects the tethered hover test information and realistic data from a scaled down model. The prop governor characteristics of the conversion maneuvers are handled by a proportional–integral controller in both the main-prop and tail-prop. This provides stable control forces during forward and backward conversions of the ducts. The conversion path between flight speed and tilt angle is defined via full-conversion flight test results. The flight results indicate that the tilt-duct UAV exhibits a unique tilt during the flight conversion from the helicopter to airplane mode and vice versa. In the conversion mode, the vehicle states of the target model are shown. This information will help establish a better understanding of the development of tilt-duct UAVs.