Research On The On-board Adaptive Model And Optimization Control Of Aero-engine

The aero-engine control system is an important part of the aero-engine system,and plays an important role in ensuring the safety,reliability and economy of the engine.This paper takes the on-board adaptive model and transient control law optimization as the main line,and carries out the research of aero-engine on-board adaptive model establishment,transient control schedule optimization and thrust control technology,which is based on the"The real-time simulation and filter model of aero-engine"project of Shenyang Aircraft Design and Research Institute.The main contents are as follows:Firstly,a nonlinear component-level model of aero-engine based on the aerodynamic thermodynamics is built up so as to provide a platform for subsequent work.Secondly,this paper proposes a method for aero-engine on-board adaptive model combining Kalman filter and nonlinear model.First of all,the system matrix is obtained by the partial derivative method,which is used as the initial value of optimization and further optimized by the least squares fitting method,thereby a state variable model is constructed at a steady state point of aero-engine.Next,a linear parameter-varying system is established within the aero-engine flight envelope and the responding linear parameter-varying Kalman filter is designed to construct the adaptive model.The simulation results show that health parameters can be estimated correctly whether at different steady-state points or a certain working range or different degradations,which ensures the on-board adaptive model can match the real engine performance.Then,the sequential quadratic programming algorithm is designed to optimize the engine transient control schedule.To begin with,realize the optimization along a constrained boundary condition which can represent the shortest transient time.Besides,the fuel flow rate is adjusted downward while other constraints are unchanged,and different transient control law under different constraints can be acquired through optimization.Further,constructing a transient time evaluation function used to calculate the transition state time under each transition state control law.Lastly,the calculated transition time and the corresponding control law are utilized to establish an interpolation table to realize the control law scheduling.The simulation results show that the proposed optimization algorithm enables the aero-engine to run along the constraint boundary under the premise of safety,ensuring the rapidity of the transition state.Finally,H_?mixed sensitivity method is adopted to realize the design of engine direct thrust controller.In the first place,the expected thrust value of the engine closed-loop control is obtained through optimization.And the direct thrust control research under the full life of the engine is conducted based on the thrust estimation of the proposed aero-engine on-board adaptive model,thereby the H infinite thrust controller is designed ultimately.The simulation results show that the proposed controller can accurately track the reference instruction and verify the effectiveness of the designed controller.