早期故障及时检测与预防维护具有很大的经济与安全意义，提出了一种基于相关向量机(RVM)的智能故障诊断方法用于检测齿轮早期故障。首先，小波包变换与Fisher准则结合，自动确定最优分解层次，并在小波包树节点能量中提取出具有最大分类能力的全局最优特征；其次，RVM用于训练故障诊断模型；最后，在线监控过程中，对连续监测的特征值做滑动平均滤波，再输入到故障诊断模型。实验表明，该方法具有很高的分类精度，RVM模型比SVM模型更适合在线故障监测。

An intelligent fault diagnosis method based on relevance vector machine (RVM) is proposed for incipient fault detection of gear. First, by combining wavelet packet transform with Fisher criterion, it is able to adaptively find the optimal decomposition level and select the global optimal features from all node energies of full wavelet packet tree. Then, the RVM is adopted to train the fault diagnosis model. Finally, to improve accuracy for online continuous fault diagnosis, moving average is applied to each feature before it is input into the fault diagnosis model. Experimental results demonstrate that the proposed method can achieve very high classification accuracy and indicate that RVM is more suitable than SVM for online fault diagnosis.