Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision

The positioning of lithium battery tabs in electric vehicles is a crucial aspect of the power battery assembly process. During the pre-tightening process of the lithium battery stack assembly, cells and foams undergo different deformations, leading to varying displacements of cells at different leve...

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Main Authors: Yueda Xu, Yanfeng Xing, Hongbo Zhao, Yufang Lin, Lijia Ren, Zhihan Zhou
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:World Electric Vehicle Journal
Subjects:
Online Access:https://www.mdpi.com/2032-6653/16/1/27
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author Yueda Xu
Yanfeng Xing
Hongbo Zhao
Yufang Lin
Lijia Ren
Zhihan Zhou
author_facet Yueda Xu
Yanfeng Xing
Hongbo Zhao
Yufang Lin
Lijia Ren
Zhihan Zhou
author_sort Yueda Xu
collection DOAJ
description The positioning of lithium battery tabs in electric vehicles is a crucial aspect of the power battery assembly process. During the pre-tightening process of the lithium battery stack assembly, cells and foams undergo different deformations, leading to varying displacements of cells at different levels. Consequently, determining tab positions poses numerous challenges during the pre-tightening process of the stack assembly. To address these challenges, this paper proposes a method for detecting feature points and calculating the displacement of lithium battery stack tabs based on the MicKey method. This research focuses on the cell tab, utilizing the hue, saturation, and value (HSV) color space for image segmentation to adaptively extract the cell tab region and further obtain the ROI of the cell tab. In order to enhance the accuracy of tab displacement calculation, a novel method for feature point detection and displacement calculation of lithium battery stacks based on the MicKey (Metric Keypoints) method is introduced. MicKey can predict the coordinates of corresponding keypoints in the 3D camera space through keypoint matching based on neural networks, and it can acquire feature point pairs of the subject to be measured through its unique depth reduction characteristics. Results demonstrate that the average displacement error and root mean square error of this method are 0.03 mm and 0.04 mm, respectively. Compared to other feature matching algorithms, this method can more consistently and accurately detect feature points and calculate displacements, meeting the positioning accuracy requirements for the stack pole ear in the actual assembly process. It provides a theoretical foundation for subsequent procedures.
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id doaj-art-68c9ebc1f49f4b52997f327f3aa5a009
institution Kabale University
issn 2032-6653
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series World Electric Vehicle Journal
spelling doaj-art-68c9ebc1f49f4b52997f327f3aa5a0092025-01-24T13:52:48ZengMDPI AGWorld Electric Vehicle Journal2032-66532025-01-011612710.3390/wevj16010027Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine VisionYueda Xu0Yanfeng Xing1Hongbo Zhao2Yufang Lin3Lijia Ren4Zhihan Zhou5School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201600, ChinaSchool of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201600, ChinaPan Asia Technical Automotive Center Co., Ltd., Shanghai 201201, ChinaSAIC GM Power Technology (Shanghai) Co., Ltd., Shanghai 201206, ChinaSAIC GM Power Technology (Shanghai) Co., Ltd., Shanghai 201206, ChinaAvatr Technology (Chongqing) Co., Ltd., Chongqing 401120, ChinaThe positioning of lithium battery tabs in electric vehicles is a crucial aspect of the power battery assembly process. During the pre-tightening process of the lithium battery stack assembly, cells and foams undergo different deformations, leading to varying displacements of cells at different levels. Consequently, determining tab positions poses numerous challenges during the pre-tightening process of the stack assembly. To address these challenges, this paper proposes a method for detecting feature points and calculating the displacement of lithium battery stack tabs based on the MicKey method. This research focuses on the cell tab, utilizing the hue, saturation, and value (HSV) color space for image segmentation to adaptively extract the cell tab region and further obtain the ROI of the cell tab. In order to enhance the accuracy of tab displacement calculation, a novel method for feature point detection and displacement calculation of lithium battery stacks based on the MicKey (Metric Keypoints) method is introduced. MicKey can predict the coordinates of corresponding keypoints in the 3D camera space through keypoint matching based on neural networks, and it can acquire feature point pairs of the subject to be measured through its unique depth reduction characteristics. Results demonstrate that the average displacement error and root mean square error of this method are 0.03 mm and 0.04 mm, respectively. Compared to other feature matching algorithms, this method can more consistently and accurately detect feature points and calculate displacements, meeting the positioning accuracy requirements for the stack pole ear in the actual assembly process. It provides a theoretical foundation for subsequent procedures.https://www.mdpi.com/2032-6653/16/1/27lithium battery tabsmachine visiondisplacement measurementHSV
spellingShingle Yueda Xu
Yanfeng Xing
Hongbo Zhao
Yufang Lin
Lijia Ren
Zhihan Zhou
Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
World Electric Vehicle Journal
lithium battery tabs
machine vision
displacement measurement
HSV
title Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
title_full Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
title_fullStr Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
title_full_unstemmed Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
title_short Multi-Cell Displacement Measurement During the Assembly of Automotive Power Batteries Based on Machine Vision
title_sort multi cell displacement measurement during the assembly of automotive power batteries based on machine vision
topic lithium battery tabs
machine vision
displacement measurement
HSV
url https://www.mdpi.com/2032-6653/16/1/27
work_keys_str_mv AT yuedaxu multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision
AT yanfengxing multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision
AT hongbozhao multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision
AT yufanglin multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision
AT lijiaren multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision
AT zhihanzhou multicelldisplacementmeasurementduringtheassemblyofautomotivepowerbatteriesbasedonmachinevision