In the last years various approaches have been proposed for automatic landing. This thesis presents the design of an automatic landing control system that has been developed using a proportional derivative (PD) type of fuzzy logic controller.
A six-degree-of-freedom nonlinear model of F16 is employed for both steps of this work. Firstly a linear PID controller is developed with standard approaches in order to follow the imposed trajectory during the landing phases, simultaneously by means of the engine thrust and the elevator. Then a nonlinear control system is designed as a Supervisory Expert Control System (SECS) using fuzzy logic for the glide path capture and the flare maneuver to converge the aircraft's path to the reference trajectory.
For these two phases the trajectory is specified in the longitudinal plane respectively as a straight line and an exponential curve, along which the aircraft has to descend.
The scaling factors of the fuzzy logic controller are optimized by means of a genetic algorithm.
The controller obtained is used to simulate the maneuver also with a modified value of the moment coefficient cm. The simulations show the improvements in the behavior of the system using fuzzy logic with respect to a linear controller.