Research On Fault Diagnosis And Fault-tolerant Control Technology Of Aviation Actuators

Aviation actuators are high-precision position servo control systems on aircraft,and are an important part of aircraft.Their performance directly affects the execution effect of aircraft control systems.As aircraft applications become more and more extensive,the requirements for aircraft become more and more demanding.The higher the coming,the higher the requirements for aviation actuators,such as high power density,high dynamic characteristics,high control accuracy and high fault tolerance,etc.,and the electromechanical actuator servo control system replaces hydraulic actuators.Motors have become an important research object and development trend of high-performance servo control systems in the aerospace field.Among them,high response speed,high fault tolerance and high control accuracy are the research hotspots of electromechanical actuators,and they are the key to achieve highperformance electromechanical actuators.The key is.This dissertation takes the aviation electromechanical actuator as the research object,and conducts research to improve its fault tolerance performance and control accuracy.The main contents include:(1)Aircraft electromechanical actuator system design,failure analysis and modeling.In order to improve the reconfigurable performance of the actuator system,an electromechanical servo system with dual CPUs and dual motors was proposed,and design indicators and overall design schemes were proposed according to actual needs.On this basis,the mechanical components of the system were selected.And the analysis and verification of key components;Next,the hardware part and software part of the controller are designed for the system,including the design of the circuit board and the switching strategy of dual CPU and dual motors.At the same time,the signal isolation processing is done to avoid The influence of electromagnetic interference;Finally,the common failures of the aero-electromechanical actuator system are analyzed,and a system model with additive failure characteristics is established;(2)Additive fault detection of aircraft electromechanical actuator system based on neural network adaptive fault observer.In view of the additive faults that may occur in the system,based on the adaptive fault observer,combined with the neural network observer,it not only considers the model uncertainty and interference robustness of the system,but also improves the observation accuracy of the fault.The fault detection sensitivity is greatly improved,and the fault detection threshold is designed to realize the early warning of system additive faults.(3)Fault-tolerant control design of aero-electromechanical actuator system.In order to take into account the control requirements of the system during normal operation and failures,on the basis of the fast terminal sliding mode,a neural network fast terminal sliding mode control system is designed to realize the control accuracy of the system during normal operation and when a failure occurs.Finally,the Lyapunov stability theorem is used to prove that the fast terminal sliding mode fault-tolerant controller based on neural network can realize the bounded stability of the system.(4)Experimental Study.Aiming at the experimental prototype of the aviation electromechanical actuator system and the designed hardware circuit board,combined with the designed observer and controller,a joint simulation and physical platform fault detection and active fault-tolerant control experiment were carried out,which verified the performance under additive faults.The feasibility of fault detection and fault tolerance control.