The Establishment Of Aero-engine Simulation Platform And Multi-objective Switching Control Design

An aero-engine is a kind of pneumatic thermodynamics system with strong nonlinearity,time-variation and complexity,and its performance will have great impact on an aircraft.Therefore,the research on aero-engine control has theoretic significance and practical value.Meanwhile,aero-engines usually run in complicated conditions with numerous safety constraints,which makes aero-engine control more difficult.In this thesis,we take two-spool turbofan engine as the research object,and the research objective is to make sure that aero-engine's performance can be improved with safety constraints by designing controllers and applying a reasonable switching strategy.The main contributions are as follows:First,we build an aero-engine simulation platform to support verification of the control algorithm that we design for an aero-engine.Second,for a nonlinear components model of an aero-engine,we design variable universe fuzzy switching controllers.We take this model as the controlled plant,and design basic fuzzy controllers,including necessary scale changing,fuzzification,membership functions selection,control rules determination,clearness calculation,switching rules establishment and so on.By designing universe scaling factor,we accomplish design of variable universe fuzzy switching controllers.The simulation shows the effectiveness of the proposed variable universe fuzzy control method.Third,for an aero-engine switching linear model,we design sliding mode switching controllers.Based on the small deviation linear model,we build an aero-engine switching linear model.Sliding mode controllers are designed for this new model.Also,the simulation shows rationality of the designed sliding mode controllers.Finally,the main results are summarized.Furthermore,some problems of aero-engine multi-objective switching control that deserve future study are discussed.