Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series

In the current workplace, most manual labor is composed of high-frequency tasks with low physical workloads. Moreover, traditional ergonomic evaluation methods often have difficulty identifying slight variations in working postures and physical workloads in manual tasks. The aim of this study is to...

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Autores principales: Kazuki HIRANAI, Akisue KURAMOTO, Akihiko SEO
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Lenguaje:EN
Publicado: The Japan Society of Mechanical Engineers 2019
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Acceso en línea:https://doaj.org/article/0c237e6ac40b4a6b97bc970033b16974
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spelling oai:doaj.org-article:0c237e6ac40b4a6b97bc970033b169742021-11-29T05:52:02ZEvaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series2187-974510.1299/mej.19-00464https://doaj.org/article/0c237e6ac40b4a6b97bc970033b169742019-12-01T00:00:00Zhttps://www.jstage.jst.go.jp/article/mej/7/1/7_19-00464/_pdf/-char/enhttps://doaj.org/toc/2187-9745In the current workplace, most manual labor is composed of high-frequency tasks with low physical workloads. Moreover, traditional ergonomic evaluation methods often have difficulty identifying slight variations in working postures and physical workloads in manual tasks. The aim of this study is to determine whether singular spectrum transformation (SST) can detect changes in human posture during manual tasks. In an experiment, eleven male participants performed lightweight material handling tasks under differing work conditions and task intervals, and an electromagnetic motion-tracking system measured their working postures. An anomaly score for each joint angle was calculated using SST, and the means, coefficients of variation (CV), and over-threshold values recorded during each experimental condition were compared. Lag is an important SST parameter for detecting how working posture differs between tasks. Therefore, the effects of changes in lag on the anomaly score were investigated. For each joint angle, the mean anomaly scores were greater under random task intervals than under constant intervals. In contrast, the CV of the anomaly score was smaller under random intervals than under constant intervals. The number of over-threshold values was significantly larger under random intervals than under constant intervals when SST was applied to the elbow flexion angle. The lag was determined according to the time of the work cycle and agreed with lag times observed in previous studies. This study concludes that the efficacy of SST was shown through detection of working posture changes in a time series, and that lag should be selected in accordance with the work cycle.Kazuki HIRANAIAkisue KURAMOTOAkihiko SEOThe Japan Society of Mechanical Engineersarticleanomaly detectionsingular spectrum transformationworking posture measurementwork analysishuman motion analysismovement variabilityMechanical engineering and machineryTJ1-1570ENMechanical Engineering Journal, Vol 7, Iss 1, Pp 19-00464-19-00464 (2019)
institution DOAJ
collection DOAJ
language EN
topic anomaly detection
singular spectrum transformation
working posture measurement
work analysis
human motion analysis
movement variability
Mechanical engineering and machinery
TJ1-1570
spellingShingle anomaly detection
singular spectrum transformation
working posture measurement
work analysis
human motion analysis
movement variability
Mechanical engineering and machinery
TJ1-1570
Kazuki HIRANAI
Akisue KURAMOTO
Akihiko SEO
Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
description In the current workplace, most manual labor is composed of high-frequency tasks with low physical workloads. Moreover, traditional ergonomic evaluation methods often have difficulty identifying slight variations in working postures and physical workloads in manual tasks. The aim of this study is to determine whether singular spectrum transformation (SST) can detect changes in human posture during manual tasks. In an experiment, eleven male participants performed lightweight material handling tasks under differing work conditions and task intervals, and an electromagnetic motion-tracking system measured their working postures. An anomaly score for each joint angle was calculated using SST, and the means, coefficients of variation (CV), and over-threshold values recorded during each experimental condition were compared. Lag is an important SST parameter for detecting how working posture differs between tasks. Therefore, the effects of changes in lag on the anomaly score were investigated. For each joint angle, the mean anomaly scores were greater under random task intervals than under constant intervals. In contrast, the CV of the anomaly score was smaller under random intervals than under constant intervals. The number of over-threshold values was significantly larger under random intervals than under constant intervals when SST was applied to the elbow flexion angle. The lag was determined according to the time of the work cycle and agreed with lag times observed in previous studies. This study concludes that the efficacy of SST was shown through detection of working posture changes in a time series, and that lag should be selected in accordance with the work cycle.
format article
author Kazuki HIRANAI
Akisue KURAMOTO
Akihiko SEO
author_facet Kazuki HIRANAI
Akisue KURAMOTO
Akihiko SEO
author_sort Kazuki HIRANAI
title Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
title_short Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
title_full Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
title_fullStr Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
title_full_unstemmed Evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
title_sort evaluating the efficacy of singular spectrum transformation in detecting working posture changes in a time series
publisher The Japan Society of Mechanical Engineers
publishDate 2019
url https://doaj.org/article/0c237e6ac40b4a6b97bc970033b16974
work_keys_str_mv AT kazukihiranai evaluatingtheefficacyofsingularspectrumtransformationindetectingworkingposturechangesinatimeseries
AT akisuekuramoto evaluatingtheefficacyofsingularspectrumtransformationindetectingworkingposturechangesinatimeseries
AT akihikoseo evaluatingtheefficacyofsingularspectrumtransformationindetectingworkingposturechangesinatimeseries
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