变工况、变载荷设备部件不同故障的特征在信号中所占比例和位置不固定,且包括大量不同场景下的原始振动信号的多尺度复杂性.对此,提出一种基于特征金字塔网络(FPN)的卷积循环神经网络(CRNN)滚动轴承故障诊断方法.利用卷积神经网络(CNN)框架,并联CNN的卷积层和循环神经网络(RNN)中的长短时记忆(LSTM)层,形成新的CRNN,以充分利用CNN对空间域信息和RNN对时域信息的学习能力;在每一层中权值共享,减少网络参数;利用FPN构建全新特征图,输入一维信号和堆叠后形成的二维信号,对传感器采集的信号进行特征提取,实现故障诊断.利用行星齿轮箱进行故障试验,并进行5折交叉验证,该方法的诊断准确率平均值为99.20%,比基本神经网络模型至少高3.62%,表明该方法诊断精度高、鲁棒性强;利用凯斯西储大学轴承数据集进行验证,证明该方法具有良好的泛用性;利用t-SNE方法对模型的特征学习效果进行可视化分析,结果表明不同故障类别特征具有良好的聚类效果.

Aimed at the problems that the proportion and position of different fault characteristics of equipment components under variable working conditions and variable load in the signal are not fixed, and include the multi-scale complexity of the original vibration signal in a large number of different scenarios, a convolutional recurrent neural network (CRNN) rolling bearing fault diagnosis method based on feature pyramid network (FPN) was proposed. Using the convolution neural network (CNN) framework, the convolution layer of CNN and the long and short-term memory (LSTM) layer of recurrent neural network (RNN) were connected in parallel to form a new CRNN, so as to make full use of the learning ability of CNN to spatial domain information and RNN to time domain information. The weights were shared in each layer to reduce network parameters. A novel feature map was constructed using FPN, and one-dimensional signal and two-dimensional signal formed after stacking were input to extract the feature of the signal collected by the sensor, and realize fault diagnosis. The average diagnostic accuracy of this method is 99.20%, which is at least 3.62% higher than that of the basic neural network model, indicating that this method has a high diagnostic accuracy and a strong robustness. Using the bearing data set of Case Western Reserve University, it is proved that the method has a good universality. The t-SNE method was used to visually analyze the feature learning effect of the model. The results show that different fault category features have good clustering effect.