In the field of bearing fault diagnosis, it is difficult to obtain a large amount of labeled data for training, and therefore it is easy to overfit the model, which makes it less robust and less generalizable. To address this problem, this article offers a novel semi-supervised contrastive learning (SSCL) method based on a multiscale attention (MSA) mechanism and multitarget contrastive learning (MCL) for rolling bearing fault diagnosis under limited labeled samples. First, the proposed SSCL utilizes improved MCL to pretrain the model as a means of capturing potentially generic features in unlabeled data. Then, semi-supervised contrast learning is constructed and based on the pretrained model combining a limited amount of labeled data and a large amount of unlabeled data to jointly learn the feature mapping and further enhance the feature extraction capability of the model through an MSA mechanism. Case Western Reserve University, the Society for Mechanical Failure Prevention Techniques, and Paderborn University are common motor-bearing datasets that are used in this article for testing the proposed technique. As a result of the experimental findings, SSCL is demonstrated to be superior to other approaches in similar situations.

The accuracy of bearing fault diagnosis is of great significance for the reliable operation of rotating machinery. In recent years, increasing attention has been paid to intelligent fault diagnosis techniques based on deep learning. However, most of these methods are based on supervised learning with a large amount of labeled data, which is a challenge for industrial applications. To reduce the dependence on labeled data, a self-supervised joint learning (SSJL) fault diagnosis method based on three-channel vibration images is proposed. The method combines self-supervised learning with supervised learning, makes full use of unlabeled data to learn fault features, and further improves the feature recognition rate by transforming the data into three-channel vibration images. The validity of the method was verified using two typical data sets from a motor bearing. Experimental results show that this method has higher diagnostic accuracy for small quantities of labeled data and is superior to the existing methods.

Under the auspice of further developing 5G mobile communication technology and integrating it with the latest advancements in the field of Industrial Internet-of-Things, this study conducts in-depth research and detailed analysis on the combination of 5G with industrial systems based on composite structures, communication network architectures, wireless application scenarios, and communication protocols. The status quo, development trend, and necessity of 5G mobile communication technology are explored and its potential in industrial applications is analyzed. Based on the current practical development level of 5G technology, by considering different requirements for bandwidth, real-time performance, and reliability in communication networks of industrial systems, this study proposes three feasible paths for the integration between 5G and industrial systems, including the method to use 5G in place of field buses. Finally, by introducing real-world cases, this study has successfully demonstrated the integration of 5G and industrial systems by extending 5G terminals as field bus gateways. This study provides valuable references for research and practice in related fields.