Transfer Learning‐Based Fault Diagnosis of Internal Combustion (IC) Engine Gearbox Using Radar Plots

Due to constant loads, gear wear, and harsh working conditions, gearboxes are subject to fault occurrences. Faults in the gearbox can cause damage to the engine components, create unnecessary noise, degrade efficiency, and impact power transfer. Hence, the detection of faults at an early stage is highly necessary. In this work, an effort was made to use transfer learning to identify gear failures under five gear conditions—healthy condition, 25% defect, 50% defect, 75% defect, and 100% defect—and three load conditions—no load, T1 = 9.6, and T2 = 13.3 Nm. Vibration signals were collected for various gear and load conditions using an accelerometer mounted on the casing of the gearbox. The load was applied using an eddy current dynamometer on the output shaft of the engine. The obtained vibration signals were processed and stored as vibration radar plots. Residual network (ResNet)‐50, GoogLenet, Visual Geometry Group 16 (VGG‐16), and AlexNet were the network models used for transfer learning in this study. Hyperparameters, including learning rate, optimizer, train‐test split ratio, batch size, and epochs, were varied in order to achieve the highest classification accuracy for each pretrained network. From the results obtained, VGG‐16 pretrained network outperformed all other networks with a classification accuracy of 100%.