Investigating the Performance of Fuzzy, PID and LQR Controllers for Control of Airplane Pitch Angle

Abstract

Airplane automated control is one of the indispensable components of the airplane. One of the controllable deviations in airplane is
controlling along the transverse axis. The main objective of this paper is to select the appropriate controller for this purpose. Three
controllers i.e. PID, fuzzy and LQR controllers are designed to control the pitch angle. After modeling and obtaining mathematical
relationships required for the desired control system, these controllers are applied separately to the mathematical model of airplane. To
evaluate the performance of the controllers, a square wave with amplitude of 11.5 degree and period of 7 seconds is considered to be able to
compare the time response of the controllers. Finally it is concluded that Fuzzy controller has lower speed due to lack of overshoot. LQR and
PID controllers' performance are almost identical but in practice the LQR controller is better to follow the desired pitch angle.