Control System Modeling And Sensor Failure Influence On Aeroengine

The aero engine control system consists of an aero engine,controller,actuator and sensors.The sensor is one of the fault-prone components,and the normality of its signal will directly affect the normal operation of the engine control system.Airworthiness Regulations CCAR33.28(engine control system clause)specifies the safety of the aero engine control system,declare that the engine control system components failure will not cause harmful consequences.In order to study the quantitative influence of sensor failure on engine performance parameters,a model-based sensor fault simulation analysis method based on the engine component model and controller control system is provided.The research result can provide initial guidance and reference for the initial safety assessment and airworthiness certification of the engine control system.The research content is divided into the following parts:(1)A component-level model of the PWX4056 aeroengine was built and the model was validated.The model of aeroengine is established by using the component method in Matlab/Simulink software.The Newton-Raphson method is used to solve the steady-state common working equations of the engine composed of power balance and flow balance,and the steady-state model is verified at the design point of the engine.The flow balance method is used to establish the dynamic model of the engine.The Euler method is used to solve the engine rotor dynamics equation and the engine dynamic model is verified.The established engine component level model provides a simulation basis for the design of subsequent controllers and the quantitative analysis of sensor failure effects.(2)The engine steady state controller parameters and the acceleration state controller parameters are designed.Based on the engine component level model,the incremental PID controller parameters are designed by trial method,and the controller parameters are designed in the engine idle state,the maximum thrust state and the intermediate state.The acceleration plan is formulated according to the limit value in the engine acceleration process,and the steady state controller and the acceleration plan are linked by the conventional Min selection logic to realize the acceleration statecontrol.The control system consisting of the aero-engine steady state controller and the acceleration state controller,which provides a basis for sensor fault simulation analysis.(3)Analyze the impact of sensor fault on engine operating conditions.The constant pressure fault of the pressure sensor is simulated,and the pressure sensor constant deviation fault is added into the engine control system,and the simulation analysis of sensor constant deviation fault effect is performed in the steady state and the acceleration state of the engine.The effect of sensor constant deviation fault on engine performance parameters can provide support and reference for the initial safety assessment and airworthiness certification of the engine control system.