Development of a Solar-Powered Unmanned Aerial Vehicle

The objective of this study was to develop technologies for the unmanned aerial vehicle (UAV) to achieve a long endurance. The air plane was driven by electric-based propulsion systems with power supplied continuously by the endless solar energy. A conceptual design was conducted for a solar powered unmanned aerial vehicle. Unlike conventional aircrafts, in this study, a vehicle was designed with consideration of equipping solar cells on the surface to generate sufficient electric power for flight. The solar plane of the new conceptual design was characterized by a hybrid lifting configuration, which was mainly consisted of a conventional wing and a lifting body, and a V-shaped tail to achieve the lightweight and guarantee large surface for using solar cells. The wing had a moderate aspect ratio to obtain better aerodynamic performance. The lifting body not only has a large surface for the solar cells to generate sufficient electric power, but also had a large volume for holding instruments near the mass center. The V-shaped tail not only had less wetted surface area and lightweight, but also played a role of winglet on the lifting body, and thus reduced drag. Ground experiments were carried out to measure the performance of the solar cell, motor, propeller thrust, structure, and so on. Flight tests were successful and performance was analyzed. Results show that the new concept of the solar plane was encouraged to achieve a long endurance flight.