Speed Regulation Control Design Based On Smooth Switching Strategy For Aero-engines

The aero-engine is a complex control system,with multiple working modes,and the operating dynamics have strong nonlinearity and time-varying characteristics.In this thesis,for a certain aero-engine,a switching system model based on a linearization model and an equilibrium manifold expansion model is established,and the controllers for subsystems are designed respectively.Besides,an improved smooth switching control strategy is proposed.Furthermore,the effectiveness of the proposed methods is verified by simulation.The main contents of the thesis are as follows:Firstly,for a certain aero-engine which is the object of our study,a two-step method of dynamic-static separation is used to establish an equilibrium manifold expansion(EME)model.Then,combining with the advantages of the linearized model and the EME model,a switching model based on the two models is established in order to improve the model accuracy and facilitate the controller design.Further,comparing the above three models with the component-level model respectively,it is verified that the switching model has higher accuracy.Secondly,the stabilization controller is designed for the linearized model and the EME model respectively.Furthermore,the switching law is designed based on the application scopes of linearized model and EME model in order to improve the model accuracy.In addition,the simulation verifies that the switching controller based on the EME model and linearization model has better control effect than a single controller.Finally,considering that the jump of the control input when the controller switches may have an adverse transient effect on the system,an innovative smooth switching control strategy has been proposed.The proposed smooth switching control method combines the idea of fuzzy control and an intelligent algorithm to ensure that smooth switching performance is maintained within any given time period while satisfying the optimization of system output performance.More importantly,applying the proposed smooth switching design method to the aero-engine control system simulation,the feasibility and effectiveness of the proposed method has been verified,with some guiding significance in engineering.