Fuzzy Logic Controller for Turbojet Engine of Unmanned Aircraft

Abstract

This paper proposes a turbojet engine controller for unmanned aircraft using Fuzzy-PI(Proportional Integral) algorithm. To prevent surge or flame out which could occur during engine acceleration or deceleration operation, the PI type fuzzy system controls the fuel flow input value. The fuzzy logic with logarithm function is designed to obtain the fast acceleration and deceleration of the engine under the condition that the operating point should stay between the surge and flame out control lines during the transient. This paper presents a fuzzy inference rule made by the logarithm function can improve the characteristics of tracking error in steady state. The proposed control scheme is proved by computer simulation using a linear engine model. Simulation results on the state space model of a turbo jet engine illustrate that the proposed controller achieves the desired performance.