A Digital Twin Framework of a Material Handling Operator in Industry 4.0 Environments
Date
2020-11
Authors
Sharotry, Abhimanyu
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Abstract
<p>The manufacturing and construction industries around the globe have poor
occupational health and safety records. Slip & fall, manual material handling (MMH)
moves, and forklift accidents are the top three causes for warehouse injuries. Statistics
from the U.S. Department of Labor, Bureau of Labor Statistics show that in
manufacturing industries, musculoskeletal disorders accounted for 34% of the "Days
Away from Work" cases in 2017. Sprains, strains, and tears accounted for the leading
type of injury in the manufacturing industry. This research presents a digital twin (DT)
approach to assess fatigue in human operators in the material handling industry. DT is an
advanced simulation tool that is an exact representation of a physical object. For data
collection and analysis, a simulation-based framework is presented. The proposed
methodology consists of three modules: Data Collection, Operator Analysis & Feedback,
and Digital Twin Development. An optical motion capture system helps develop the DT,
which captures simulated material handling activities similar to those in an actual
environment. For a pilot study, participants were selected from the university population
to perform a series of 'lifting' MMH activities. The participants' physical attributes, body
kinematics, and their rating of perceived exertion were measured throughout the
experiment. Fatigue was measured as a factor in the subjects' joint angles and analyzed
via a dynamic time warping algorithm. To identify the accumulation of biomechanical
fatigue, we use an exponentially weighted moving average control chart.</p>
<p>This research aims to conceptualize a DT of an operator and propose a tool that enables the understanding and analysis of the factors that influence human variability and
error while performing MMH tasks. The proposed methodology was able to detect
biomechanical fatigue in subjects performing MMH tasks and justify the need for a true
DT of an operator for fatigue evaluation in the Industry 4.0 era.</p>
Description
Keywords
Digital twin, Industry 4.0, Manual material handling, Operator, Motion capture, Dynamic time warping, EWMA Control Chart, Biomechanics
Citation
Sharotry, A. (2020). <i>A digital twin framework of a material handling operator in industry 4.0 environments</i> (Unpublished thesis). Texas State University, San Marcos, Texas.