摘要
针对非线性、非平稳航空发动机双发差异信号,提出利用瞬时能量密度谱凸显微波动信号这一方法获得双发差异波动值出现的时间。通过总体经验模式分解(ensemble empirical mode decomposition, EEMD)结合希尔伯特变换(Hilbert transform, HT)求解信号的HT谱与瞬时能量密度水平,从频率、幅值与时间三方面给出信号特征。以燃油流量为例,分析了航空发动机气路参数差值在巡航段的波动情况。结果表明:在2 095、3 600 s左右发动机燃油流量差值出现微弱波动,且后者波动幅值为前者的1/5,频率范围集中在0~0.2 Hz。2 095 s信号波动是由飞机飞行高度、航向变化及加速度变化引起的,3 600 s信号波动是加速度变化导致的。由瞬时能量密度谱获得航空发动机参数微波动发生的精确时间,并与快速存取记录仪(quick access recorder, QAR)记录的同时刻其他相关数据进行对比,追溯发动机燃油流量变化的原因,判断航空发动机是否存在故障。
According to nonlinear and nonstationary dual-engine difference signal of aero-engine, instantaneous energy density spectrum methods were proposed to display the micro-fluctuation signals. Hilbert spectrum and instantaneous energy density level were solved by ensemble empirical mode decomposition(EEMD) combined with Hilbert transform(HT), and signals characters such as frequency, time and amplitude were obtained. Taking fuel flow as an example, fluctuations of gas path parameters difference of aircraft engine during cruising were analyzed. Results show that the fuel flow difference of left and right aircraft engine fluctuates slightly at 2 095 seconds and 3 600 seconds within 0 Hz to 0.2 Hz frequency domain and the latter fluctuation amplitude is 1/5 times smaller than that of the former. Signal fluctuation occurred at 2 095 s is caused by flight altitude, course deviation and acceleration change, while signal fluctuation at 3 600 seconds is caused by acceleration change. The time of dual-engine differences are obtained by instantaneous energy density spectrum and other aero-engine parameters at the same time are compared with the dual-engine difference to traces the reasons of engine changes, which can evaluate the fault of aircraft engine.
作者
周春华
叶子龙
芦吉云
贾奥男
吕雨薇
ZHOU Chun-hua;YE Zi-long;LU Ji-yun;JIA Ao-nan;Lü Yu-wei(Laboratory of Space Mechanical and Thermal Integrative Technology,Shanghai Institute of Satellite Engineering,Shanghai 200240,China;State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;College of Civil Aviation,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《科学技术与工程》
北大核心
2020年第23期9655-9659,共5页
Science Technology and Engineering
基金
国家自然科学基金(51775263,51405223)
江苏高校优势学科建设工程资助项目(PAPD)
中央高校基本科研业务费资助项目(NJ201812)。
关键词
双发差异监测
飞行数据
总体平均经验模式分解
信号重构
瞬时频率
dual-engine difference monitoring
flight data
ensemble empirical mode decomposition
signal reconstruction
instantaneous frequency
