Transition control and redundancy management for a tilt rotor UAV using genetic algorithms

The design of Flight Control Systems for tilt-rotor UAVs can be challenging for the management of the hovering to forward flight transition and vice-versa and for the presence of redundancy in the control actuators. The preliminary design phase for the E-Pteron tiltrotor UAV was almost completed and a first estimate of the inertial and dynamic characteristics of the aircraft was carried out. A dynamic model simulating both hovering and forward flight conditions was formulated and a preliminary control logic was identified. The proposed Flight Control System architecture is based on a non-linear fixed structure controller articulated in two main blocks isolating control laws from control allocation. The non-linear fixed structure was devised through engineering considerations on the dynamics involved, while the gain tuning was performed formulating a non-linear constrained optimization problem, its solution having been found running genetic algorithms. Local stability around flight conditions of interests was imposed as a hard constraint, performance were formulated using quadratic functions. Numerical simulations of the transition phases were carried out showing that the resulting controller exhibits promising responses.