DEVELOPMENT OF OWAS MOTION SENSOR-BASED ERGONOMIC ASSESSMENT METHOD WITH REAL-TIME FEEDBACK

• Main Author: Fauziah, Anisa
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79435
• Institution: Institut Teknologi Bandung

Work-related musculoskeletal disorders are one of the leading causes of industrial injury in developed and developing countries. One of the efforts to minimize these disorders is to conduct an ergonomic assessment. Generally, today's ergonomics assessment method was observational using a worksheet filled out by an ergonomics expert. This study proposed to develop an ergonomic assessment method that integrates the Ovako Working Posture Analysis System (OWAS) with Inertial Measurement Units (IMUs), which was called the OWAS IMUs. This assessment method can provide real-time feedback to workers. Developing the ergonomic assessment method begins with conducting a field study. Field studies were carried out with direct visits to one of the manufacturing industries to observe several production tasks. Based on the characteristics of the production task, the appropriate assessment method to use was OWAS. Aspects of work that were considered risk factors for musculoskeletal disorders were the back, arms, legs, and weight being handled. These risk factors were considered in the sensor system design using eight IMUs, which were then placed on the back, arms, and legs based on the OWAS assessment method. In the proposed system, the body segment angle values obtained from each IMUs sensor are stored in a log and uploaded to an online database using an application on a PC, namely IMU Monitor. The OWAS IMUs were then validated and compared with the results of manual measurements. Measurements show that the angle in the system has good validity and reliability with a root mean square error of 2o-8o, Spearman correlation above 0.75, test-retest reliability shows a significant relationship between the two measurement results (p<0.001) and the value intraclass correlation coefficients 0.5-0.9. The OWAS IMUs score test and manual measurement results showed the same results. The system succeeded in providing real-time feedback on the posture experienced by workers, which was shown in a warning system in the form of sound and vibration. Further research can integrate several other observation methods with IMUs so that assessment methods become more easier and more reliable.