An Effective Predictive Maintenance Framework for Conveyor Motors Using Dual Time-Series Imaging and Convolutional Neural Network in an Industry 4.0 Environment

The ascent of Industry 4.0 and smart manufacturing has emphasized the use of intelligent manufacturing techniques, tools, and methods such as predictive maintenance. The predictive maintenance function facilitates the early detection of faults and errors in machinery before they reach critical stages. This study suggests the design of an experimental predictive maintenance framework, for conveyor motors, that efficiently detects a conveyor system's impairments and considerably reduces the risk of incorrect faults diagnosis in the plant; We achieve this remarkable task by developing a machine learning model that classifies whether the abnormalities observed are production-threatening or not. We build a classification model using a combination of time-series imaging and convolutional neural network (CNN) for better accuracy. In this research, time-series represent different observations recorded from the machine over time. Our framework is designed to accommodate both univariate and multivariate time-series as inputs of the model, offering more flexibility to prepare for an Industry 4.0 environment. Because multivariate time-series are challenging to manipulate and visualize, we apply a feature extraction approach called principal component analysis (PCA) to reduce their dimensions to a maximum of two channels. The time-series are encoded into images via the Gramian Angular Field (GAF) method and used as inputs to a CNN model. We added a parameterized rectifier linear unit (PReLU) activation function option to the CNN model to improve the performance of more extensive networks. All the features listed added together contribute to the creation of a robust future proof predictive maintenance framework. The experimental results achieved in this study show the advantages of our predictive maintenance framework over traditional classification approaches.