基于多尺度AlexNet网络的健康因子构建方法

针对目前健康因子构建方法存在的单调性和趋势性不够理想的问题，提出一种基于多尺度AlexNet网络的轴承健康因子构建方法。该方法首先利用连续小波分析将原始振动加速度信号转换为时频图，将时频图作为输入对多尺度AlexNet网络进行训练；然后利用训练好的网络在线构建测试轴承健康因子；最后根据健康因子评估准则评估初步构建的健康因子，利用评估结果调整网络参数，实现迭代优化，进一步提高健康因子的单调性和趋势性。实验对比分析结果表明：该方法显著提高了健康因子的单调性与趋势性，不需要进行特征提取、特征选择、特征融合等步骤，具有较高的构建效率和泛化性。

Construction method of bearing health indicator based on multi-scale AlexNet network

The monotonicity and trendability of the health indicator constructed by the traditional method is not very ideal. To solve these problems, a bearing health indicator construction method based on multi-scale AlexNet network is proposed. First of all, the original vibrational acceleration signal is transformed to time-frequency map, which is considered as the input of the multi-scale AlexNet network, by continuous wavelet transformation. Then, the health indicator of test bearing is constructed online by the trained multi-scale AlexNet network. Finally, the constructed health indicator is evaluated by metrics, the evaluation results are then used to adjust the network parameters to realize the iterative optimization. The experiment results show that the health indicator constructed by the proposed health indicator construction method has better trendability and monotonicity. In addition, this method does not rely on feature extraction, selection and fusion, which enhances the construction efficiency and generalization.