Research On Performance Seeking Control Technology Of Variable Cycle Engine

The Variable Cycle Engine(VCE)is an advanced multi-design engine that adjusts the thermodynamic cycle parameters by changing the geometrical characteristics of the rotating components,the adjustable inlets at the ducts,and the adjustable flaps at the exits to change the engine cycle.The mode,which in turn enables the engine to maintain high propulsion efficiency and low fuel consumption over a wide flight envelope,is an aero engine that meets the power requirements of the next generation of fighters.The advanced control system is a necessary condition to ensure that the adaptive cycle engine fully exerts the design performance under the premise of safety and stability in the flight envelope.Performance optimization control technology,as a branch of engine integrated control technology,is an effective method for deep mining engine potential.In this paper,the following researches are carried out on variable cycle engine modeling,unmeasurable parameter estimation,multivariable control and performance optimization methods:1.Research on variable cycle engine modeling technology.Based on the analysis of the working principle and working mode of the variable cycle engine,the characteristic components of the variable cycle engine are studied.The active mode selection valve,the passive selection valve and the ducted ejector are analyzed and modeled.Based on the component method,the steady-state and dynamic models of the variable-cycle engine are established,and the influence of the initial value selection on the convergence speed and accuracy is solved.The quantum particle swarm(Quantum Particle Swarm)is proposed.,QPSO)hybrid solution algorithm.The accuracy of the established model and the effectiveness of the proposed algorithm are verified by comparison with the commercial software Gasturb.2.Research on adaptive model modeling technology of variable cycle engine.Firstly,the causes and laws of the degradation of aeroengine performance parameters are summarized,and the adaptive model structure of the variable cycle engine is proposed.Then,the influencing factors of real-time in the solution of variable cycle engine model are analyzed.The cycle iteration for component thermodynamic calculation is the main reason for the large time consumption of the model single-step calculation.The component thermal calculation method in the model is processed in real time.Improve the real-time nature of the model.Secondly,the dynamic inertia effect,mass storage effect and energy storage effect of the variable cycle engine are analyzed.The state variable model of the variable cycle engine with degradation parameters is established by the method of small deviation linearization.Finally,the research on the unmeasurable parameter estimation method of variable cycle engine is carried out.The Adaptive Unscented Kalman Filter(AUKF)is proposed and linear Kalman Filter(LKF)is added.The Extended Kalman Filter(EKF)and the Unscented Kalman Filter(UKF)were compared and verified.3.Research on control law and control method of variable cycle engine.Firstly,the analysis of variable cycle engine control requirements is carried out,and the limit range of variable cycle engine adjustable variable and surge margin,total turbine front temperature and other state quantities are summarized.Based on the traditional turbofan engine control law,the variable cycle engine stability is analyzed.State control requirements.Then,through the analysis of the influence of the variable geometry of the variable cycle engine on the engine performance,the control law of the modal switching of the variable cycle engine is studied.Finally,aiming at the problem of multi-variable output tracking controller design under the condition of system uncertainty and external disturbance in variable-cycle aeroengine,an augmented model reference adaptive sliding mode control method based on LQR method is proposed.Based on the state-tracking sliding mode control method,the adaptive law of the upper bound of the system perturbation matrix and the upper bound of the external disturbance is derived based on the strict stability condition of the Lyapunov function to improve the control effect of the variable cycle engine.4.Research on optimization method of variable cycle engine performance.Firstly,the structure of the variable circulation engine performance optimization control system is designed.Based on the aircraft mission profile,the requirements of the aircraft for variable cycle engine performance under different missions are analyzed.Then,according to the performance requirements and working principle of the variable cycle engine,the optimization objectives and constraints of the performance optimization of the variable cycle engine are analyzed.The problem of variable cycle engine performance optimization is summarized as a numerical optimization problem with nonlinear inequality and equality constraints.The sequential quadratic programming(SQP)algorithm and differential evolution algorithm are used to optimize the performance of the variable cycle engine.Finally,according to the principle of differential evolution algorithm and the characteristics of variable cycle engine performance optimization problem,the differential evolution algorithm is improved by gradually reducing the variation and cross operation in the iterative process to improve the efficiency of the algorithm.5.Research on comprehensive simulation and verification technology of variable cycle aeroengine.An integrated digital simulation platform for variable cycle engine based on S-Function was established in Matlab environment.Based on the model established by C language,the variable-cycle engine simulation model in Matlab environment is established by S-Function using object-oriented thinking.Based on Simulink,an adaptive sliding mode controller for variable cycle engine was built and connected with the model to form a complete simulation platform of the variable cycle engine and its controller.Through the established digital simulation platform of variable cycle engine,the real-time model of variable cycle engine,control law,multivariable control method and performance optimization method are comprehensively verified.In the above related research on variable cycle engine performance optimization control technology,the corresponding numerical simulation results and comparative analysis are given.The results show that the variable cycle engine modeling method,unmeasured parameter estimation method,adaptive sliding mode control method and performance optimization method proposed in this paper are feasible and effective.