Nonlinear Modeling And Fault Analysis Of Flight Control Electromechanical Actuation System

Multi-electric/all-electric aircraft is the trend of modern civil aircraft.Electromechanical actuation system(EMA)has been gradually applied to the flight control surfaces of modern civil aircraft as a new and efficient actuating device,but as a multivariable-strongly coupled complex systems,whose failure modes are unclear,fault performance is not easily identified,the novel design features introduce novel failure modes,which increase the difficulty of system fault impact analysis and become difficult for airworthiness review.In order to clarify the failure mode of EMA and its impact on faults,this paper establishes an accurate EMA nonlinear model,and focuses on EMA’s failure modes,fault modeling methods,the impact of faults on the system,and the fault features.The research contents mainly include: analysis of the EMA,the study of the working principle of the system including the drive motor,the mechanical transmission structure,and the ball screw,and points out typical nonlinear factors and establishes the nonlinear model,analysis the influence of non-linear factors on the system.As the novel and unique failure modes of EMA,non-instructional signal faults need to be clarified in terms of their specific failure modes and fault locations.The research of fault modeling is based on the typical failure modes that often occur and have great differences between failure mechanisms and can represent a type of failure;on this basis,the impact of various failure modes on the system and the influence of nonlinear factors on the system are simulated and analyzed,assess the level of fault impact,summarize the regularity;influence of spectral data by fast Fourier transform analysis method,system fault,extracting characteristic,determining a relationship between the failure affects the failure modes.Through the research,it is possible to specify the novel failure modes of the EMA non-command signals,and to provide typical failure mode and injection methods.Summarizing the regularity conclusions,the assessment criteria for failure impact levels are derived,the impact of various failure modes on the system and the influence of nonlinear factors on the system are summarized,and the fault feature extraction method is obtained.The focus of the impact of the failure is extracted.The EMA airworthiness review elements provide the basis and provide theoretical support for the design of fault detection and isolation.This is not only the theoretical basis for system design performance optimization,but also the basis for clarifying system fault characteristics and improving system reliability.