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介绍了机载变排量变转速一体化电动静液作动器(EHA-VPVM,Electro-Hy-drostatic Actuator with Variable Pump displacement and Variable Motor speed)的系统结构,根据EHA-VPVM早期故障信号非平稳、时变等特点,采用一种新的时频分析方法希尔伯特黄变换(HHT,Hilbert-Huang Transform)进行信号分析.针对HHT方法的模态混叠和虚假本征模态函数问题,提出两点改进:通过集合经验模式分解算法抑制模态混叠的发生;采用相关系数法保留真实本征模态函数.对EHA-VPVM工程样机进行早期故障诊断实验,用Hilbert边际谱和HHT谱分析永磁无刷直流电机两种工作状态下的振动信号.实验结果表明:改进HHT方法较好解决了HHT的模态混叠和虚假本征模态函数问题,能准确提取研究对象的早期故障特征,对EHA-VPVM早期故障具有良好的诊断效果.
The system structure of EHA-VPVM (Electro-Hy-drostatic Actuator with Variable Pump displacement and Variable Motor speed) is introduced. According to the early failure signal of EHA-VPVM, , Time-varying and so on, a new time-frequency analysis method Hilbert-Huang Transform (HHT) is used for signal analysis.According to the modal aliasing and pseudo-intrinsic mode function problems of HHT method, Two improvements are proposed: suppression of modal aliasing through the aggregation of empirical mode decomposition algorithm, and preservation of real intrinsic mode function by the correlation coefficient method. The early fault diagnosis experiments of EHA-VPVM engineering prototype are carried out. Hilbert marginal spectrum and HHT spectrum The vibration signals of the permanent magnet brushless DC motor under two working conditions are analyzed.The experimental results show that the improved HHT method solves the problem of modal aliasing and fake intrinsic mode function of HHT well and can accurately extract the early failure of the research object Features that have good diagnostic results for early failures of EHA-VPVM.