【作者】 杨凯；

【导师】 陈前；

【作者基本信息】 南京航空航天大学 ， 车辆工程， 2008， 硕士

【摘要】 振动分析是进行传动系统的状态监测与故障诊断的重要手段。传动系统振动信号中常常含有大量噪声,这使得信号和噪声的频谱在频域内发生了重叠。本文旨在研究适于传动系统的振动信号处理方法。盲源分离(BSS)是目前信号处理中最热门的新兴技术之一,而将盲源分离技术应用于实际机械振动信号处理方面,还不多见。本文以传动系统故障诊断实验为基础,展开这方面的研究。本文介绍了小波分析和盲源分离(BSS)的原理,研究了小波阈值去噪算法和基于负熵的快速固定点算法及其改进的牛顿迭代形式。在实际情况下,传动系统的振动信号受到噪声影响,本文提出了综合采用时延自相关和小波去噪的方法对信号进行预处理,再用改进的快速固定点算法进行信号分离,即“小波去噪-盲源分离-小波去噪”方法。之后,搭建了传动系统故障试验平台,获得了关于齿轮振动信号的丰富的数据。同时,对轴承故障数据进行了研究,得到了若干分析结果。通过分析验证了所研究的算法的有效性和适用性,为盲源分离技术在传动系统上的应用打下了基础,同时也为传动系统故障诊断提供了一个新的手段。更多还原

【Abstract】 Vibration analysis has been widely used in the condition monitoring and fault diagnosis of the transmission system. Usually, there is much noise in the vibration signals of transmission system, which makes the spectra of signal and noise overlap in the frequency domain. So, this paper mainly aims at the research of vibration signals processing techniques that suitable for the transmission system. Now Blind Source Separation (BSS) is one of the hottest and most exciting topics in the fields of signals processing, but its real application on the mechanical vibration is few reported. This paper will do such research on the basis of transmission vibration experiment.This paper deals with the research on wavelet analysis and BSS, and then obtains some related algorithms of wavelet de-noising, FastICA and its improved Newton iterations. As the real conditions of vibration signals are often corrupted by noise, a new method is proposed to select the delayed autocorrelation and wavelet de-noising as a signal preprocessing, and then using the improved FastICA to separate the preprocessed signals, which called“wavelet de-noising-BSS-wavelet de-noising”in this paper. After that, a faults experimental platform for the transmission system is established, and a lot of gear vibration signals are acquired with it. At the same time, a research on the bearing fault data is completed, and some useful analysis results are also obtained. By the experiments, this paper checks and proves the practicability and applicability of the new method. These experiments not only build a foundation for the real application of BSS but also provide a new method for fault diagnosis on the transmission system.更多还原