Online bearing fault diagnosis using numerical simulation models and machine learning classifications

•Motivated by DT, an online bearing fault classification scheme is presented.•Monitoring signal and PCC are used to online modify the numerical models.•Numerical training samples are employed to ML models for faut classifications.•Experiments of a bearing with faults verify the performance of the scheme. Digital twin (DT) is the embodiment of the most advanced achievements of the current simulation technology theory development and the direction of intelligent development in the future. However, it is a great challenge to really integrate it into practical project application. Motivated by DT, an application method combining numerical simulation model and machine learning classification is proposed to show the advantages of digital twin. To ensure the reliability of the twin model, it is necessary to build a simulation model using a mature dynamic model, and modify it through the Pearson correlation coefficient (PCC) which is a kind of model online learning. Then, the required fault type is introduced by modifying the relevant fault influence factors, which is synchronously inserted into the normal operation model to obtain the normal, fault and other simulation numerical data. Finally, the machine learning model is used to predict the probability of each fault and feedback the impact value to the actual operation to guide the adjustment of actual parameters and the determination of maintenance plans. The experimental results show that this method can effectively predict the possibility of bearing failure synchronously and guide the adjustment and maintenance of actual bearing operating parameters. [Display omitted]