Study On The Impact Of Aero-Engine Transient Performance Under Speed Sensor Impulse Fault

Airworthiness regulations for aero-engines stipulate the safety of control system:the "single point fault" of engine control system components can not lead to hazardous consequences,and the applicant must complete the system safety assessment to determine the fault or failure that may cause thrust change or affect the working characteristics of engine.In order to study the influence of sensor fault on aero-engine transient performance parameters,a simulation analysis method of sensor fault influence based on control system mathematical model is proposed in this paper.The research results can provide guidance and reference for safety evaluation,airworthiness compliance verification and failure influence analysis in the early development of control system.It can also provide troubleshooting ideas for fault location of control system.This paper mainly includes the following three parts:(1)In order to analyze the impact mechanism of speed sensor impulse fault,an integrated control system simulation platform is built in MATLAB/Simulink environment,which includes steady-state controller,transition state controller and limit protection controller,and has anti wind-up function.Simulation verification and analysis of small transition state and large transition state are carried out.The results show that the thrust dynamic response speed is fast and the settling time is short.At the same time,the integrated design of multiple limit protection controllers can automatically adjust the fuel flow command to safely control the engine acceleration and deceleration operation and avoid the engine output variables beyond its constraint boundary.Therefore,the engine closed-loop control system simulation platform meets the technical indicators,and can be used for the subsequent analysis of the impact mechanism of sensor impulse fault.(2)Firstly,the reason of impulse fault of speed sensor and the characteristics of fault signal are studied.Then,the influence mechanism of speed sensor fault on aero-engine small transition state and large transition state output variables and key performance indicators is simulated and analyzed.Then,on the premise that the measured signal fails,the sensitivity of the limit value and anti wind-up gain value in the protection circuit to the fault signal is analyzed.Finally,From the perspective of fault signal parameters,the negative influence of sensor fault signal amplitude on aero-engine dynamic response speed is studied.(3)In order to reduce the negative impact of speed sensor impulse fault on aero-engine transient acceleration performance,an optimization design method of aero-engine limit protection controller based on safety margin evaluation was proposed.Whether the limiting protection controller should be activated or not is decided by the active judgment of the key output variables of the engine.In the safety margin evaluation module,the intelligent optimization algorithm particle swarm optimization algorithm is used to search the reasonable and reliable value within the given boundary.The simulation results show that the optimization design method can effectively reduce the sensitivity of the control system to the sensor fault signal,and the logic structure of the optimization design method is simple,and the original control system framework is slightly changed,which has a very strong engineering practical significance.