Abstract
Tail-sitter is one of the simplest VTOL aircraft. However, because the flight control is difficult, past researches used special equipments to facilitate controlling. To make aerial robots smaller and simpler, we are developing an aerial robot that excludes these special equipments. Flight of VTOL aircraft can be broadly divided into three phases: vertical flight (including hovering), level-flight, and transition flight. This paper describes transition flight between level-flight and hovering of our tail-sitter VTOL aerial robot. The transition flight was constructed based on strategy that transition finishes in the shortest time and altitude is kept constant. To achieve the transition strategy, modeling and simulation were prepared. Finally, feasibility of the transition strategy and effectiveness of control system were confirmed by flight tests.
