Unmanned aerial vehicle(UAV) that have been recently commercialized can largely be divided into fixed-wing aircraft and rotor-craft in its style and flight characteristics. Although fixed-wing aircraft represent higher power efficiency, higher speed, longer flight distance, and larger loading weight than rotor crafts, it has a disadvantage of requiring space like a runway for taking off and landing and that leads to bring more accidents than rotor craft.
In the case of rotor craft, although it can implement vertical taking off and landing and represents various flight modes (hovering, steep bank turns, and low-speed flight), it requires both precision taking off control and attitude control. The objective of this study is to develop a quad-tilt rotor system that shows a simple structure and can implement vertical taking off and landing by combining advantages in both fixed-wing aircraft and rotor craft.