An approximate non-linear model for aeroengine control

Abstract

Control-oriented non-linear modelling is the requirement of reliable non-linear control for aeroengines. The complex engine model must be simplified such that advanced non-linear control techniques can be applied. Some simplified engine models lose the physical interpretability, and further, the analysability of stability and performance of the real closed-loop system, which eventually hinders their industrial implementation. Linear parameter-varying model attains certain success in aeroengine control in recent years, but its potential drawback has also been proposed in theoretical research. This article proceeds to reveal this problem from a model perspective. Then, an approximate non-linear model for aeroengine control is introduced, followed by an identification procedure for more efficient modelling. Simulations show good precision of this model in capturing the non-linear behaviour of a turbofan engine. Theoretically, controllers designed with this model can guarantee local stability and performance for the real plant.