本文以液压系统常用的液压阀（溢流阀、减压阀、调速阀）为研究对象，基于高阶累积量和高阶谱，采用小波、分形和神经网络等理论方法对液压阀的振动信号进行分析，实现液压阀的故障识别。 液压阀在正常与不同故障状态下工作时，其振动信号通过双谱分析谱图各有差异。正常状态和故障状态的双谱相比，在分布范围和谱峰多少均体现出不同的特性。双谱维切片较双谱更具体更直观地表征液压阀故障信息的频率位置，且计算量也相对减少。两种谱分析方法均十分有效地对液压阀进行故障识别。在此基础上，以高阶累积量的耦合性质理论为依据，将采集的原始信号变换为复数信号，再通过复数高阶累积量的各种不同的耦合方式分析各种故障产生的结果，将正常信号和...In this paper,the usual hydraulic valves (reducing valve, overflow valve and speed-regulating valve) in hydraulic system were studied. Based on higher-order cumulants (HOC), higher-order spectrum (HOS) and its coupling features, wavelet、fractal and neural network theories were used to analyze the vibration signals extracted from hydraulic valves, and the fault recognition were accomplished. Autor...学位：工学博士院系专业：信息科学与技术学院电子工程系_电路与系统学号：2312009015369
