航空液压系统故障模拟试验台设计

Design of Fault Simulation Test Bench for Aviation Hydraulic System

飞机液压系统故障诊断是飞机故障预测与健康管理(Prognostics and Health Management,PHM)领域的难点。随着液压系统向高压化方向发展,其渗漏、增温、压力脉动导致的管道断裂,以及回油压力过高等诸多液压系统的致命故障发生的概率增加。通过液压系统试验台构成分析及仿真验证,建立了完善的飞机液压系统故障模拟试验台。制订液压系统故障模拟试验方案,在模拟试验台完成试验。采集正常状态、不同工况、预置故障试验和加速寿命试验的数据,获得可靠的飞机液压系统关键征兆参数。通过对比分析不同工况数据的时频特征,确定均方根可用于时域故障特征分析,小波包能量谱可用于频域故障特征分析。利用时频故障特征,通过正常及预置故障试验数据,验证了所提出的检测方法的有效性。

Fault diagnosis of the aviation hydraulic system is a difficult problem in the field of aircraft prognostics and health management(PHM).With the development of the hydraulic system towards high pressure,the probability of fatal failures of many hydraulic systems increases,such as pipeline fracture caused by leakage and temperature increase,pressure pulsation,and high return oil pressure.Through the component analysis of the test bench and simulation verification,a comprehensive fault simulation test bench for the aircraft hydraulic system is established.A fault test plan for the hydraulic system is formulated,and the test is completed on the simulation test bench.Reliable key precursor parameters of the aircraft hydraulic system are obtained by collecting data from normal state,different working conditions,preset fault tests and accelerated life tests.By comparing and analyzing the time-frequency characteristics of data under different working conditions,it is determined that the root mean square can be used to analyze the time-domain fault features,and the energy spectrum of wavelet packet can be used for frequency-domain fault feature analysis.By using time-frequency fault features and normal and preset fault test data,the effectiveness of the proposed detection method is verified.