针对目前可靠性分析方法必须采用很大的统计样本数据和采用概率统计方法计算齿轮箱可靠性的不足,提出了利用齿轮箱运行状态信息来实现小样本条件下齿轮箱可靠性估计的方法:基于小波信息熵归一化的可靠性估计。基于小波信息熵归一化的齿轮箱可靠性估计是对齿轮箱运行工程中的振动信号利用第二代小波包进行分解和重构计算,得到分解频带信号,然后计算分解频带信号的相对能量和小波信息熵归一化,最后根据小波信息熵归一化获得反应齿轮箱运行状态可靠性的指标——可靠度。在对齿轮箱可靠性估计的应用表明所提出的方法有效、合理,为齿轮箱在缺乏大样本数据、非概率统计条件的可靠性估计提供了方法。
The traditional reliability analysis has such drawbacks that it must be dependent on the large sample statistical data, and use the probability statistics method to calculate the reliability of gearbox. Based on these, a new method which uses gearbox running status information to implement reliability assessment under the condition of small sample is proposed. It is the reliability evaluation method based on the normalized wavelet information entropy. The reliability assessment based on the normalized wavelet information entropy method is to make decomposition and reconstruction computa- tions on the vibration signals of gearbox by virtue of the second generation wavelet package to get de- composed signals in sub--frequency bands. Then,the relative energy of these decomposed signals and the normalized wavelet information entropy are calculated. Finally, the degree of reliability which acts an important reliability index is acquired by using the normalized wavelet information entropy to evalu- ate reliability of gearbox. The application of the method to evaluate reliability of gearbox demonstrated that the proposed approach is effective and reasonable. This study provided a way to calculate reliabili- ty of gearbox which is lack of large sample statistical data and is independent of probability statistics.