Design of a flight controller for an X4-flyer rotorcraft

The X4-Flyer rotorcraft is particularly interesting for its high maneuverability given by four independent rotors, and its reliability due to the limited number of moving parts. Applications of such vehicles in an unmanned configuration are numerous for both civil and military missions. This thesis presents a detailed study of the X4-Flyer rotorcraft dynamics, possible disturbances (e.g., extreme initial conditions, wind, and collisions), and a complete approach to design a trajectory-tracking controller. The non-linear controller uses a combination of feedback linearization and several nested PID loops to achieve this task. The controller, rotorcraft dynamical model, and disturbance models are implemented in a MATLABRTM/SIMULINKRTM program. The model was then tested with multiple trajectory tracking cases in order to validate performances and robustness of the controller algorithm.