基于改进EMD的旋转机械耦合故障诊断方法研究.docVIP

 基于改进 EMD 的旋转机械耦合故障诊断方 法研究# 时培明1,2，李庚1,2，刘彬1* 5 10 15 20 25 30 （1. 燕山大学电气工程学院，秦皇岛 066004； 2. 燕山大学测试计量技术及仪器河北省重点实验室，秦皇岛 066004） 摘要：针对旋转机械耦合故障的诊断问题，提出一种基于改进 EMD（Empirical Mode Decomposition）的诊断方法。该方法结合相似极值延拓和加余弦窗函数运算的优点，解决 了延拓部分不精确和加窗函数后使原信号发生改变的问题，提高 EMD 方法的运算精度。用 该方法对存在裂纹碰摩故障的转子-轴承系统振动信号进行分解，得到含有故障特征的本征 模式函数(Intrinsic Mode Function,简称 IMF)，再经希尔伯特变换获得相对应的边界谱和希尔 伯特谱。通过与单一故障特性对比，诊断出该故障系统转子圆盘振动信号既有裂纹引起的高 频成分也有碰摩引起的低频成分，得到耦合故障的特征，证明该方法的有效性。 关键词：故障诊断；旋转机械；改进 EMD；裂纹；碰摩 中图分类号：TH 133 Study on coupling faults of rotary machinery diagnosis method based improved EMD SHI Peiming1,2, LI Geng1,2, LIU Bin1 (1. Institute of Electrical Engineering, Yanshan University, Qinhuangdao 066004; 2. Hebei Key Laboratory of Measurement Technology and Instrumentation, YanShan University, Qinhuangdao 066004) Abstract: Aiming at coupling faults diagnosis of rotary machinery, based on improved EMD (Empirical Mode Decomposition) method of faults diagnosis is proposed. With the method combining advantages of similar extreme a extension and cosine window function, the inaccuracy of extension and original signal changed because of window function are solved, and the precision of EMD is improved. Through decomposing vibrating signal from rotor-bearing system with coupling faults of crack and rub-impact, IMF (Intrinsic Mode Function) containing fault feature is obtained, meanwhile, by the Hilbert transformation gets relevant boundary spectrum and Hilbert spectrum. Contrasting with fault feature of single fault, the vibrating signal from rotor disk of fault system is diagnosed with both containing high-frequency component due to crack and low-frequency component due to rub-impact, and the coupling faults feature is acquired, while proving the method is effective. Key words: fault diagnosis; rotating machinery; improved EMD; crack; rub-impact 35 0 引言 在旋转机械转子系统故障中转轴裂纹和动静碰摩尤为常见，也是引起机械系统失效的主 要原因。目前国内外学者对裂纹和碰摩单一故障研究较多，提出了许多有效方法来诊断裂纹 故障和碰摩故障[1-5]。但在实际转子中，常常出现裂纹故障和碰摩故障同时存在的情况。这 40 种耦合故障转子的动力学行为较单一故障转子更