Design, production and flight experiments of a tiltable propeller unmanned aerial vehicle

This dissertation presents the design, flight mechanics and flight demonstration studies of a novel tilt-propeller vertical take-off and landing unmanned aerial vehicle. The aircraft, discussed in this study consists of two counter rotating tilt-propeller pairs placed on both wing tips and a counter propeller pair placed between the tail booms. The airplane has a capability of vertical take-off and landing as well as conventional take-off and landing. Both wing tip propeller pairs have been designed with a capability of tilting about ninety degrees around y-axis of the aircraft. In this dissertation, the weight estimation approach has been discussed and initial sizes of the aircraft have been represented. The equations of motion and kinematics equations have been derived and the aerodynamic/propulsion force and moment models have been established. With the established models, the trim condition calculations have been derived for hover, transition and cruise flight modes. The longitudinal stability characteristics for hover, transition and cruise flights have been analyzed after linearization of the equations of motion. The stability analysis has been performed via calculating the eigenvalues of the system matrix of the state space model and placing them on the s-plane. The control strategies for all three flight modes have been evaluated and a control algorithm used for controlling the aircraft has been presented. The radio, flight control card, sensors and the electric/electronic connection for automatic control applications have been defined. The orientation estimation study, which is a requirement for aircraft control, has been explained. The manufactured indoor and outdoor test platforms for the experimental studies and the final aircraft manufacturing processes have been described briefly. Lastly, the flight demonstrations performed indoor and outdoor have been summarized. The results of final flight test have been depicted via graphical representations.