Design of fractional PID controller in time-domain for a fixed-wing unmanned aerial vehicle

In the past years Unmanned Aerial Vehicles (UAVs) have received considerable attention from the scientific community. The trajectory control is a fundamental block that a flight control system must properly address. However, a recent approach based on fractional calculus has shed a new light into this area, allowing the well tested PID controller to be improved even further. One advantage is that optimization of fractional PID controller can start from parameters obtained by any method developed to classical PID. Thereafter it has two additional parameters that adjust the integral and derivatives orders allowing us to fine tune the controller. In this work we developed a fractional PID to control the lateral channel of a small-fixed wing UAV based on a time-domain optimization criteria. The controller was validated using FlighGear flight simulator, using the SenecaII aircraft. The results show that the identification of the system model plays a crucial role in the performance, and that the approximation from fractional order to integer order can degrade the performance of the controller.