Hardware-in-the-loop simulation of an attitude control with switching actuators for SUAV

The attitude control law for fixed-wing small unmanned aircraft proposed in this paper is constructed based on two phases of a flight: stable flight and maneuvering flight. In the maneuvering flight, the aircraft deflects the main control surfaces (ailerons and elevator), whereas on the stable flight only the trim tabs are deflected. The switch between the two flights is done when the aircraft enters a zone in which the difference between the aircraft´s attitude and the reference value that the airplane needs to reach is less than a predetermined value. The control laws are implemented on an on-board computer and are validated though Hardware-In-the-Loop (HIL) simulations, between the hardware and the flight simulator X-Plane, which simulates the unmanned aircraft dynamics, sensors, and actuators. The results presented prove that this implementation can reduce the rise time and the overshoot, compared with traditional implementations.