Modeling,Redundancy Technology And Integrated Evaluation Of Elevator System

The motions of the aircraft around the three axes: yaw,roll and pitch,are controlled by flight control system.So the reliability and performance of flight control system are crucial to the aircraft and safety of flight.As an important part of aircraft,it is necessary to take appropriate measures to improve the reliability of flight control system,and the redundancy technique is an effective way to accomplish this goal.The introduction of redundancy technology makes the flight control system become more complicated,for such complex fault-tolerant systems,traditional reliability analysis method is not applicable.Model-based reliability analysis has outstanding advantages on quantification of system performance and reliability,and it is an important direction of the design of flight control system at present.Flight control system includes rudder,elevator,and aileron control system.In this thesis,the elevator system is selected as the research object.The main work and research results are as follows:(1)The nominal model and fault models of the elevator system are established by using Matlab / Simulink toolbox;(2)Integrated evaluation of the reliability and performance of the elevator system is completed,and analysis of the influence of the component failure parameters on the system is accomplished,and the weak points of the system are found out;(3)Based on the system weak points,introducing fault detection,isolation and reconfiguration(FDIR)mechanism to the simple dual-channel architecture improved the original redundancy technique.And we verified the effectiveness of the FDIR mechanism by evaluation tool.(4)Redundancy technology on component level is designed for the servo valve position transducer and actuator control electronics device by Stateflow,and its effectiveness is verified by the evaluation tool.