Ergonomic-Centric Methods for Workplace Design in Industrialized Construction
Creators: Wang, Jingwen
Publisher: name: University of Alberta Library
Year: 2022

<p>As the leading cause of nonfatal occupational injuries, work-related musculoskeletal disorders account for approximately 33% of all occupational injuries and illnesses in the United States and approximately 44% of such injuries in Alberta, Canada. The risk of developing a work-related musculoskeletal disorder is closely related to the physical demands associated with awkward body postures and repetitive motions. In industrialized construction, poor workplace design may increase the probability of injury and work absenteeism, leading to schedule overruns and decreased production rates. Thus, this research investigates and develops ergonomic-centric methods to automatically evaluate the continuous motions in operational tasks for the purpose of workplace design and modification in industrialized construction.<br>
To mitigate the risk of developing a work-related musculoskeletal disorder, various observational rule-based ergonomic posture assessment methods have been developed and widely used to facilitate ergonomic risk evaluation in various industrial sectors. However, the applicability and reliability of rule-based ergonomic posture assessments to automatically evaluate continuous motions have not yet been examined. The current practice of using these assessments for automated evaluation of continuous motions is challenged in three notable respects: (1) inaccuracy of the ergonomic risk assessment results, attributable to human perception errors and subjectivity during observations, as well as measurement errors and instrument limitations when using vision-based approaches to estimate body joint angles; (2) lack of consideration of the standard motion time feature when analyzing the ergonomic risks of continuous motions in operational tasks; and (3) overestimation (in existing methods for assessing ergonomic risk in continuous motions) due to a failure to account for the effect of natural posture sway, as well as ambiguous posture categorization in the adjustment risk rating process in existing ergonomic risk assessment methods. <br>
To overcome these challenges, a systematic and objective framework is proposed by which to automatically assess the risks of continuous motions in construction tasks and thereby achieve an ergonomic-centric workplace design method that overcomes human perception errors and measurement limitations, considers standard motion time features, and accounts for the effect of natural posture sway. The three main contributions of this research are that it (1) improves the accuracy of rule-based ergonomic risk assessment methods by incorporating fuzzy logic in order to better capture the gradual transitions characteristic of continuous human motion; (2) adjusts the motion time in ergonomic risk assessment of continuous motions by integrating the predetermined motion time system; and (3) eliminates the detrimental effect of natural posture sway on continuous motion assessments by identifying and adapting the acceptable posture sway magnitudes of body joints in the motion capture experiments. A series of laboratory experiments are presented that demonstrate the feasibility and effectiveness of the proposed framework for assessing ergonomic risks of continuous motions in workplace design and modification to facilitate occupational health and safety in industrialized construction.</p>