Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks

Statistical process control (SPC) charts are commonly used to monitor quality characteristics in manufacturing processes. When monitoring two or more related quality characteristics simultaneously, multivariate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" displ...

Full description

Bibliographic Details
Main Authors: Chuen-Sheng Cheng, Pei-Wen Chen, Yu-Chin Hsieh, Yu-Tang Wu
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/11/15/3291
_version_ 1797586377918906368
author Chuen-Sheng Cheng
Pei-Wen Chen
Yu-Chin Hsieh
Yu-Tang Wu
author_facet Chuen-Sheng Cheng
Pei-Wen Chen
Yu-Chin Hsieh
Yu-Tang Wu
author_sort Chuen-Sheng Cheng
collection DOAJ
description Statistical process control (SPC) charts are commonly used to monitor quality characteristics in manufacturing processes. When monitoring two or more related quality characteristics simultaneously, multivariate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> control charts are often employed. Like univariate control charts, control chart pattern recognition (CCPR) plays a crucial role in multivariate SPC. The presence of non-random patterns in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> control charts indicates that a process is influenced by one or more assignable causes and that corrective actions should be taken. In this study, we developed a deep learning-based classification model for recognizing control chart patterns in multivariate processes. To address the problem of the insufficient representation of one-dimensional (1D) data, we explore the advantages of using two-dimensional (2D) image data obtained from a threshold-free recurrence plot. A multi-channel deep convolutional neural network (MCDCNN) model was developed to incorporate both 1D and 2D representations of control chart data. This model was tested on multivariate processes with different covariance matrices and compared with other traditional algorithms. Moreover, the effects of imbalanced datasets and dataset size on classification performance were analyzed. Simulation studies revealed that the developed MCDCNN model outperforms other techniques in identifying multivariate non-random patterns. For the most significant one, our proposed MCDCNN method achieved a 10% improvement over traditional methods. The overall results suggest that the developed MCDCNN model can be beneficial for intelligent SPC.
first_indexed 2024-03-11T00:22:24Z
format Article
id doaj.art-5df2a3ba76c94baeb325208c6ffa3331
institution Directory Open Access Journal
issn 2227-7390
language English
last_indexed 2024-03-11T00:22:24Z
publishDate 2023-07-01
publisher MDPI AG
record_format Article
series Mathematics
spelling doaj.art-5df2a3ba76c94baeb325208c6ffa33312023-11-18T23:14:41ZengMDPI AGMathematics2227-73902023-07-011115329110.3390/math11153291Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural NetworksChuen-Sheng Cheng0Pei-Wen Chen1Yu-Chin Hsieh2Yu-Tang Wu3Department of Industrial Engineering and Management, Yuan Ze University, No. 135, Yuan-Tung Road, Chung-Li District, Taoyuan City 32003, TaiwanDepartment of Industrial Engineering and Management, Yuan Ze University, No. 135, Yuan-Tung Road, Chung-Li District, Taoyuan City 32003, TaiwanDepartment of Industrial Engineering and Management, Yuan Ze University, No. 135, Yuan-Tung Road, Chung-Li District, Taoyuan City 32003, TaiwanDepartment of Industrial Engineering and Management, Yuan Ze University, No. 135, Yuan-Tung Road, Chung-Li District, Taoyuan City 32003, TaiwanStatistical process control (SPC) charts are commonly used to monitor quality characteristics in manufacturing processes. When monitoring two or more related quality characteristics simultaneously, multivariate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> control charts are often employed. Like univariate control charts, control chart pattern recognition (CCPR) plays a crucial role in multivariate SPC. The presence of non-random patterns in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> control charts indicates that a process is influenced by one or more assignable causes and that corrective actions should be taken. In this study, we developed a deep learning-based classification model for recognizing control chart patterns in multivariate processes. To address the problem of the insufficient representation of one-dimensional (1D) data, we explore the advantages of using two-dimensional (2D) image data obtained from a threshold-free recurrence plot. A multi-channel deep convolutional neural network (MCDCNN) model was developed to incorporate both 1D and 2D representations of control chart data. This model was tested on multivariate processes with different covariance matrices and compared with other traditional algorithms. Moreover, the effects of imbalanced datasets and dataset size on classification performance were analyzed. Simulation studies revealed that the developed MCDCNN model outperforms other techniques in identifying multivariate non-random patterns. For the most significant one, our proposed MCDCNN method achieved a 10% improvement over traditional methods. The overall results suggest that the developed MCDCNN model can be beneficial for intelligent SPC.https://www.mdpi.com/2227-7390/11/15/3291statistical process controlmultivariate control chart patternMCDCNNrecurrence plot
spellingShingle Chuen-Sheng Cheng
Pei-Wen Chen
Yu-Chin Hsieh
Yu-Tang Wu
Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
Mathematics
statistical process control
multivariate control chart pattern
MCDCNN
recurrence plot
title Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
title_full Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
title_fullStr Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
title_full_unstemmed Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
title_short Multivariate Process Control Chart Pattern Classification Using Multi-Channel Deep Convolutional Neural Networks
title_sort multivariate process control chart pattern classification using multi channel deep convolutional neural networks
topic statistical process control
multivariate control chart pattern
MCDCNN
recurrence plot
url https://www.mdpi.com/2227-7390/11/15/3291
work_keys_str_mv AT chuenshengcheng multivariateprocesscontrolchartpatternclassificationusingmultichanneldeepconvolutionalneuralnetworks
AT peiwenchen multivariateprocesscontrolchartpatternclassificationusingmultichanneldeepconvolutionalneuralnetworks
AT yuchinhsieh multivariateprocesscontrolchartpatternclassificationusingmultichanneldeepconvolutionalneuralnetworks
AT yutangwu multivariateprocesscontrolchartpatternclassificationusingmultichanneldeepconvolutionalneuralnetworks