Authors:
Sara Santos
1
;
Duarte Folgado
1
;
João Rodrigues
2
;
Nafiseh Mollaei
2
;
Carlos Alberto Rosado Fujão
3
and
Hugo Gamboa
2
;
1
Affiliations:
1
Associação Fraunhofer Portugal Research, Rua Alfredo Allen 455/461, 4200-135 Porto, Portugal
;
2
Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação (LIBPhys-UNL), Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
;
3
Volkswagen Autoeuropa, Quinta da Marquesa, 2954-024 Q.ta do Anjo, Portugal
Keyword(s):
Ergonomics, Industry, Musculoskeletal Disorders, Inertial Sensors, Motion Capture, Risk Score.
Abstract:
The repetitive nature of manufacturing processes is identified as a risk factor for the onset of musculoskeletal
disorders. For prevention, the operator’s exposure risk is measured through ergonomic risk scores which are
often associated with a workstation, ignoring the variability among operators. Moreover, the score values
hinder a comprehensive interpretation by occupational physicians. Observation methods require significant
effort, preventing accurate and continuous evaluation. The conducted study developed a solution using inertial
sensors for automatic operator risk exposure in the manufacturing industry. Two experimental assessments
were conducted: laboratory validation, performed by 14 subjects, using an optical motion capture system as
a reference; and field evaluation, with 6 participants, acquired on a real automotive assembly line, served as
the basis for an ergonomic risk evaluation study. Through the research, it was implemented an upper-body
motion tracking algorithm
relying on inertial information, to estimate the angular orientation of anatomical
joints. An adjusted ergonomic risk score, based on direct measurements was developed allowing an ergonomic
evaluation which also has an explanation approach, based on the comprehensive analysis of the angular risk
factors. Direct measurements fasten the ergonomic feedback, consequently, the evaluation can be extended to
more operators, ultimately preventing work-related injuries.
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