Pitch Rate Damping of an Aircraft by Fuzzy and Classical PD Controller

Aircraft dynamics are in general nonlinear, time varying, and uncertain. A control system (classical control systems) designed for a flight condition, may not provide the desired stability and performance characteristics in case of deviation from the equilibrium point. There are numerous studies regarding flight control in the literature. One of them is fuzzy flight control system. Fuzzy logic controllers (FLCs) from their inception have demonstrated a vast range of applicability to processes where the plant transfer function is not defined but the control action can be described in terms of linguistic variables. FLC's are also being used with improved performance instead of “classical" controllers where the plant transfer function is known. Most of the applications about the design of fuzzy flight control are in simulation level. In this study, the design of fuzzy and classical PD controller for the pitch rate damping system is analyzed and the results for a two-engined jet fighter aircraft are evaluated in a MATLAB coded program. Key-Words: Aircraft, flight control, pitch rate, classical PD control, fuzzy and fuzzy PD control.