Landing autopilot design for an UAV

Hanköylü, Merve
In this thesis, a landing autopilot for an UAV (IAI Pioneer RQ-2) is designed based on a nonlinear MATLAB model implemented with MATLAB/Simulink. In order to control the movement of the UAV at lateral and longitudinal axes, a speed, an altitude, a heading angle (direction) and a yaw rate controllers are designed. Controller design procedure is started with determination of different trim points of the aircraft. Next, the corresponding initial states and initial inputs are obtained. The model is linearized about those trim points and the gain values are determined. The resultant gain scheduled controller is used on the non-linear model. The response of the aircraft to these controllers is tested in a constrained landing area that is constructed with respect to applicable aviation regulations. The aircraft position is investigated whether it is inside or outside of this safe landing area. If it is inside, an optimized landing path set is obtained. The steepest descent method is used for multidimensional search and parabolic fit method is used for one dimensional search (as line search) in the optimization phase. In case it is outside the defined landing area a special algorithm which takes the aircraft into the desired region is applied. In addition, the area is allowed to move as much as possible depending on the situation with special regards to the length of the runway. Also a lateral position controller is designed in order to provide the reach of the aircraft to the main landing path.
Citation Formats
M. Hanköylü, “Landing autopilot design for an UAV,” M.S. - Master of Science, Middle East Technical University, 2011.