Design of a Pitch Attitude Autopilot for a Business Jet Aircraft

Abstract

The design of an aircraft autopilot controller that provides a fast and stable response to pilot commands, and which maintains this performance throughout the entire flight envelope, provides a challenging problem to flight control engineers. The main objective of this thesis is to design a longitudinal autopilot system for a business jet aircraft. To be more specific, the autopilot system that is designed is a pitch-attitude controller. It is assumed that the aircraft under investigation is subjected to some degree changes in elevator angle, which in turn, causes an oscillatory motion of the airplane. In order to minimize the effect of these oscillations, a proportional (P) controller, proportional-integral (PI) controller and a proportional-integral-derivative (PID) controller are designed for both, the short and long periods of motions. For the short period of motion, it is found that the P controller is the optimal controller. On the other hand, the PID controller is found to be the optimal controller for long period of motion.