Development of a Web-Based Diagnostic Tool Using Acoustic Testing and Computer Vision

Acoustic testing is a technology that covers various machinery failure modes, including bearing and gear failures. This technology is superior to vibration analysis for gear and bearing condition monitoring. This paper aims to offer the maintenance world a critical technological advance by developing a web-based tool that, using pretrained convolutional neural networks and spectrograms, allows the diagnosis of gearboxes from recordings obtained with industrial acoustic testing tools. The resulting model is tested against human specialists to assess its actual world performance. A modified agile methodology was implemented to develop the research systematically. The type of approach is mixed since it has qualitative parts, such as specialists involved in obtaining the ultrasonic data and classifying them, and quantitative parts, such as validating the precision of the model based on established validation metrics. By using a pretrained model and then performing a fine-tuning with heterodyne ultrasound recordings from gearboxes in good and bad condition, a training accuracy of 93% was achieved. Then, tests were carried out to validate false positives and negatives in which it was possible to obtain 0% and 6.7% scores, respectively. This model was incorporated on a web platform to create the diagnostic tool whose input variable is the recording, and the output variables are its spectrogram, the prediction of whether it is in good or bad condition, and the probability of both possibilities.