基于小波理论和循环统计量分析的滚动轴承故障诊断

发布时间：2018-06-18 12:43

本文选题：循环统计量 + 小波理论　；参考：《辽宁工程技术大学》2012年硕士论文

【摘要】：滚动轴承是旋转设备中最为常用且关键的器件，其能否正常工作直接影响整个机械设备，甚至生产线的运行状态和职工的安全等等。因此，研究轴承的诊断技术，有利于避免事故的发生以及维修体制的变革，具有非常重要的理论价值和实际意义。由滚动轴承自身结构的对称性，以及旋转（往复）的运行方式，使得当其发生损伤时引起的冲击调制现象，导致振动信号呈现循环平稳的特性，从而本文深入地研究了基于循环统计量分析的滚动轴承的振动信号的特征提取的方法。主要内容有： 1）详细讨论了循环统计量理论，以及它们地解调性能。通过对Hilbert变换包络解调和CAF解调性能的比较，得出CAF对于滚动轴承振动信号具有更好的分析效果，并且通过计算循环频率等于故障特征频率时的CAF，简化计算，然后对其取模、FFT变换能够提取特征信息。 2）旋转机械的早期损伤会引起非常微弱的冲击调制，往往淹没在强大噪声信息当中，应用小波理论来对早期微弱信息进行强化，也就是强化早期信号的微弱的循环平稳的特性，也为继续对信号做循环谱分析做好充足准备。 3）最后，通过多个试验研究，，对轴承不同类型的故障，分别做了功率谱、包络谱和循环谱分析，对比分析结果，验证理论研究成果地正确性及有效性。
[Abstract]:Rolling bearing is the most commonly used and key device in rotating equipment. Whether it can work properly or not will directly affect the operation state of the whole mechanical equipment and even the safety of the workers and staff. Therefore, it is of great theoretical value and practical significance to study the diagnosis technology of bearing, which is helpful to avoid the accident and the change of maintenance system. Due to the symmetry of the rolling bearing's own structure and the rotating (reciprocating) operation mode, the shock modulation phenomenon caused by the damage caused by the rolling bearing causes the vibration signal to take on the characteristic of steady cycle. Therefore, the method of feature extraction of rolling bearing vibration signal based on cyclic statistical analysis is studied in this paper. The main contents are as follows: 1) the theory of cyclic statistics and their demodulation performance are discussed in detail. By comparing the performance of Hilbert transform envelope demodulation and caf demodulation, it is concluded that caf has better analysis effect for rolling bearing vibration signal, and the calculation is simplified by calculating the CAF when the cycle frequency is equal to the fault characteristic frequency. Then the FFT transform can extract the characteristic information. 2) the early damage of rotating machinery will cause very weak impulse modulation, which is often submerged in the information of strong noise. The wavelet theory is used to strengthen the weak information in the early stage, that is, to strengthen the weak cyclic stationary characteristic of the early signal, and to make sufficient preparations for the continued cyclic spectrum analysis of the signal. 3) finally, through several experiments, The power spectrum, envelope spectrum and cyclic spectrum are analyzed respectively for different types of faults of bearing. The results are compared to verify the correctness and validity of the theoretical research results.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3;TN911.7

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