【作者】 于庆江；

【导师】 王金东；

【作者基本信息】 大庆石油学院 ， 机械电子工程， 2007， 硕士

【摘要】 分形是一门新的学科,它特别适用于分析非线性系统,而将分形用于机械设备故障诊断则是近年来故障诊断技术发展的新动向。可以采用分形方法分析机械系统的非线性信号,从中提取出特征信息,并与其它的分析方法相结合,共同实现机械设备的故障模式识别与故障诊断。本文以2D12往复压缩机为研究对象,制定了运用分形方法对其进行故障诊断的试验方案,包括:数据的获取和采集,特征参数的提取和故障诊断方法等。在特征参数的提取中采用关联维数和李雅谱诺夫指数作为系统的特征参数,重点讨论了关联维数计算方法和计算参数的选择。针对往复式压缩机的振动信号的非平稳特性,引入了小波消噪,以便能够准确提取分维数。结合几种典型的动力系统模型,对已知信号进行验算,并讨论了参数和噪声对计算结果的影响,提出了影响关联维数的几个重要参量的确定方法和取值范围,并对盒维数进行了简要的分析。在2D12往复压缩机故障分形分析与诊断实例部分,对不同工作状态下的压缩机不同部位加速度信号的关联维数进行了分析,结果表明,关联维数对设备故障比较敏感,能够反映复杂系统的动态特性。李雅谱诺夫指数可以判断压缩机是否处于混沌状态,与关联维数结合可以提高故障诊断的准确率。最后针对往复机械振动信号特点,开发了故障诊断软件。更多还原

【Abstract】 Fractal is a new subject and it is especially fit for researching nonlinear system. Recently signal processing methods based on fractal have been applied to mechanical system fault diagnosis. The objective of the proposed research is to develop a method based on fractal theory for analyzing the nonlinear signals of mechanical system. This method will provide further useful information about the underlying .dynamics. It is possible to implement mechanical system fault diagnosis by using this method combined with other signals analysis methods.The research objective of this article is 2D12 reciprocating compressor, make a experiment based on the application of fractal, including the obtaining and collecting of data ,pick-up of character parameter, the fault diagnosis method and so on. during the course of pick-up of character parameter apply correlation and lyapunov exponent to be the character parameter, have important attachment to discuss the choice of the calculating method of correlation dimension and calculating parameter, aim at unstable characteristic of vibration signal of reciprocating compressor to analyse, apply wavelet to de-noise ,guarantee to get the fractal dimension exactly, combine several typical dynamic system, use the procedure to calculate the known signal, and discuss the influence of parameter and noise to the result, propose several methods to ensure parameter and value range influencing correlation dimension, and analyse to boxing dimension.On the part of fault fractal analysis and diagnosis instance of 2D12 reciprocating compressor ,with correlation dimension to analyse to the reciprocating compressor acceleration signal of different working (fault) condition and different parts, the result shows that correlation is very sensitive to fault of equipment and can reflect dynamic characteristic of complex mechanical system, combined with lyapunov exponent to judge whether all the fault conditions of compressor situate in chaos condition, in the end aim at characteristic of vibration signal of reciprocating machinery. Develop fault diagnosis software.更多还原