Document Type : Review Article
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Master of Science, Department of Aerospace Engineering, K. N. Toosi University of Technology, Tehran, Iran
Assistant Professor, Department of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran
A literature review of the Tilt Rotor/Tilt Wing (TR/TW) Unmanned Aerial Vehicles (UAVs) is presented in this paper from the flight mechanics and control points of view. Firstly, the advantages as well as the challenges of the TR/TW UAVs are studied, from the design, aerodynamic, flight dynamic and control viewpoints. Next, a chronicle of the most important researches conducted about the TR/TW UAVs is reported. Then, these TR/TW UAVs are categorized based on the overall configurations, rotor arrangements, engine/rotor positions, and engine/rotor types. Next, a comprehensive flight dynamic modeling of the TR/TW aircraft is introduced that may provide a complete and consistent set of the dynamic equations for any type of the TR/TW regardless of the configurations and rotor arrangements. Afterwards, a survey is carried out about the trim and stability of the TR/TW within the hover and transition phases of flight. Finally, different control methods and control strategies utilized for the attitude and altitude control of the TR/TW UAVs are categorized based on their pros and cons. Since this paper covers the flight mechanics and control of the TR/TW UAVs, it may assist designers in making decisions about the most critical aspects of a new design based on the previous studies.