EXTRACTING REGIONS OF INTEREST AND DETECTING OUTLIERS FROM IMAGE DATA
2023 (English) Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE credits
Student thesis
Abstract [en]
Volvo Construction Equipment (CE) are facing the challenge of vibrations in their wheel loaders that generate disruptive noise and impact the driver's experience. These vibrations have been linked to the contact surface between the crown wheel and pinion gear in the vehicles drive-axles. In response, this thesis was created to develop an Artificial Intelligence (AI) system, which can identify outliers in a dataset containing images of the contact surfaces between the crown wheel and pinion gear. However, the dataset exhibits variations in image sharpness, exposure and centering of the crown wheel, which hinders its suitability for machine vision tasks. The varying quality of the images poses the challenge of accurately extracting relevant features required to analyze the images through machine learning algorithms.
This research aims to address these challenges by investigating two research questions. (1) what method can be employed to extract the Region of Interest (ROI) in images of crown wheels? And (2) which method is suitable for detection of outliers within the ROI?
To find answers to these questions, a literature study was conducted leading up to the implementation of two architectures: You Only Look Once (YOLO) v5 Oriented Bounding Boxes (OBB) and a Hybrid Autoencoder (BAE). Visual evaluation of the results showed promising outcomes particularly for the extraction of ROIs, where the relevant areas were accurately identified despite the large variations in image quality. The BAE successfully identified outliers that deviated from the majority, however, the results of the model were influenced by the differences in image quality, rather than the geometrical shape of the contact patterns.
These findings suggest that using the same feature extraction method on a higher-quality dataset or employing a more robust segmentation method, could increase the likelihood of identifying the contact patterns responsible for the vibrations.
Place, publisher, year, edition, pages 2023. , p. 35
Keywords [en]
Artificial Intelligence (AI), Machine Vision, Outlier Detection, Autoencoders, Neural Networks, Region Of Interest (ROI)
National Category
Computer Sciences
Identifiers URN: urn:nbn:se:mdh:diva-62933 OAI: oai:DiVA.org:mdh-62933 DiVA, id: diva2:1763770
External cooperation
Volvo Construction Equipment; Mälardalen Industrial Technology Center
Subject / course Computer Science
Supervisors
Examiners
2023-06-202023-06-072023-06-20 Bibliographically approved