Motion Tracking Smart Work Suit With a Modular Joint Angle Sensor Using Screw Routing

Activity data of workers can be used to manage their safety and working processes. To date, the adoption of motion measuring systems in industrial sites has been limited, due to cost and noisy environments. In this study, a motion-tracking smart work suit is presented to monitor the movements of workers. This system comprises modular joint-angle sensors that utilize a BoASensor mechanism, a conventional work suit with added sensor sleeves, and a monitoring device. The modularized joint-angle sensor can be easily attached or detached onto or from the normal work suit, improving its usability and washability. This suit could experience relative motion and deformation between the body, degrading sensor robustness, unlike conventional motion sensing suits. The screw sensor routing method is proposed to minimize the coordination effect between the sensor and skeletal system during body movements. Various postures recorded with the suit exhibited root mean square errors lower than 7.75%$\ $from the elbow range of motion (150°) compared with the inertial-measurement-unit-(IMU)-based motion tracker. It was determined that there exists statistical significance between the proposed screw-routing method and the IMU in precision, thereby demonstrating sensing robustness with various upper limb motions. Additionally, the linearity analysis revealed that screw-routing has the highest linear behavior. The proposed work suit is expected to be utilized in preventing industrial accidents at various sites, owing to its low production cost and high accessibility.