Research On Fault Diagnosis Of Carrier-based Aircraft Arresting And Landing Gear

As an important equipment to ensure the safe arresting of carrier-based aircraft,the stable operation of arresting landing gear is of great significance for the army to perform training and combat tasks.Compared with major military powers,China has problems in the use and diagnosis of arresting landing gear,such as short equipment use time,less diagnostic experience,less operation data accumulation,and low degree of automation and informatization.The arresting landing gear has a complex structure and many components,and there are many sources of failure.At present,the maintenance of the arresting landing gear is mainly based on periodic maintenance,which can ensure the reliable operation of the equipment to a certain extent and reduce the probability of failure.However,repairing or replacing the components of the arresting landing gear without accurately grasping the operating status of each component will not only waste resources,but also affect the timely response of the equipment to tasks.Therefore,it is very necessary to carry out research on fault diagnosis of arresting landing gear.When the equipment has faults or will have faults,it is of great significance to quickly realize fault identification and fault location to ensure the safe and stable operation of arresting landing gear.The corresponding mathematical model is established according to the structure and working principle of arresting landing gear.The AMESim multidisciplinary complex system modeling software is used to establish the simulation model of the sheave damper and the arresting landing gear in the early stage of arresting.The former determines the appropriate opening diameter of the throttle valve,the latter obtains the damping characteristics of the mass of the landing carrier aircraft of 22.7t（50000lb）and the initial speed of the landing of 74.6 m s（145 knot）,and then the research results of the US military standard MIL-STD-2066 and related literature comparing.The results show that the average error of simulation results is 8.7%,which verifies the rationality and feasibility of the simulation model.Then,the arrest simulation experiment is carried out for the carrier-based aircraft under the conditions of different masses and the same initial landing speed and different initial landing speeds and the same mass.The results show that the arrest system can realize the landing arrest task of carrier-based aircraft under various standard working conditions.The arrest displacement is within 100 meters and the arrest time is 3～4 s,which realizes the purpose of constant length sprint.Based on the analysis of the working principle of main hydraulic components and the variation law of various parameters,the fault simulation models of sheave damper and arresting landing gear are established,and the operation data under typical faults are obtained.The results show that the faults such as internal leakage,external leakage,oil pollution and blockage in the system will cause changes in the distribution of oil pressure,flow rate and temperature in hydraulic components such as hydraulic cylinders,constant-length sprint valves and energy storage devices,which will affect the force of the carrier-based aircraft to block the hook,and the motion parameters of the carrierbased aircraft will also change.After fault simulation,the simulation sensor is used to collect the pressure sample data in the hydraulic cylinder,and the particle swarm optimization（PSO）is used to optimize the deep belief network（DBN）algorithm to realize fault diagnosis.The confusion matrix and evaluation index are used to analyze the diagnosis results.The results show that the method has high reliability and accuracy,which lays a research foundation for further intelligent fault diagnosis of arresting landing gear.