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Abstract
With the requirements of the advanced propulsion systems for aircraft control performance increasing, it has attracted the attention to design more efficient controller that is based on the nonlinear model over the flight envelope directly. A nonlinear aircraft engine control method based on generalized minimum variance approach is studied. A nonlinear autoregressive with extra input aircraft engine model for a certain turbofan engine is built and is chosen as the control plant in this study. Then, a controller is designed for the identification model based on the nonlinear generalized minimum var-iance theory. And simulation results manifest the controller to satisfy the requirements of the tracking with the transient process and the regulation with the steady process.
Keywords
Aircraft engine, nonlinear generalized minimum variance, nonanalytical mathematical model
Date received: 19 February 2016; accepted: I August 2016
Academic Editor: Mario L Ferrari
(ProQuest: ... denotes formulae omitted.)
Introduction
With the relevant technology fields developed in, for example, machinery, electronics, materials, and so on, the performance of aircraft engine is continuously improved, and the number of control variables is also increasing.1 In traditional hydraulic system, engine control laws were designed primarily using classical control design methods, namely, frequency response and/or time-domain methods. It was always single loop, which means one input variable and one output variable.2 However, today, the number of advanced propulsion system control variables has also been reached 15-25.3,4 The F119 has eight control variables in 1990s,5 and the PW1128 engine equipped in the F16-XL also has up to 24 control variables.6 The linear control theories about multivariable are abundant, such as linear quadratic Gaussian (LQG) or loop transfer recovery (LTR)7 9 and Hn robust control.10 12 The nonlinear control such as sliding mode control,13,14 fuzzy control,15 17 adaptive control, and neural networks , has also been investigated for engine control. It is reported that American engineers had researched the linear quadratic method to apply it for the engine control and had adopted the LQG or LTR method in the Design Method for Integrated Control Systems (DMICS) research programs.23 Apart from this, there is no other information reported, and the traditional approach gain scheduling is still the primary method to solve the problem in practical project.24
This phenomenon can be attributed to the following...