Due to current trends in the manufacturing industry, such as mass customization, manual operations contribute drastically to the overall costs of a product. Methods-Time-Measurement (MTM) identifies ...the optimization potential of manual workplaces, which significantly influences a worker’s productivity. However, traditional MTM requires great efforts to observe and transcribe manual assembly processes. Yet, various digital approaches exist that facilitate MTM analyses. While most of these approaches require the existence of real workplaces or cardboard mock-ups, it would be beneficial to conduct a virtual MTM in earlier phases of production planning. However, the quality of virtual MTM analyses compared to traditional MTM conducted in reality has not been assessed yet. This paper is addressing it by conducting a comparative user study with 21 participants completing the same task both at a real and virtual workplace, which they access via virtual reality technology. Our results show that participants’ MTM-2 values achieved at the VR workplace are comparable to those at the real workplace. However, time study data reveals that participants moved considerably slower in VR and thus needed more time to accomplish the task. Consequently, for the measurement of manual work in VR, it is even necessary to utilize predetermined times, such as MTM-2 since time study data is insufficient. This paper also serves as a proof of concept for future studies, investigating automated transcription systems that would further decrease the efforts conducting MTM analyses.
Digital human modeling tools support proactive ergonomics in optimizing work tasks and workplace layouts. Empirical-statistical model based tools are often used to estimate the force exertion ...capability of the operators. This work is intended to serve as an initial probing into the usability of a musculoskeletal model based software, AnyBody Modeling Systems (AMS), in evaluating the force exertion capability at different points in the workspace and for various exertion directions. As a first step, it focuses on the modeling approach and the accuracy of one-handed isometric strength estimates of AMS. An existing literature database was used to compare the predicted strength at 8 hand locations and in 26 exertion directions, while simulating the empirical postures. The results show a correlation coefficient of 0.7 between the simulated and the experimental strength. AMS emphasizes the biomechanical advantages in strength due to the alignment of force exertion direction with the shoulder. Additionally, some discrepancies have been identified and discussed.
•This work investigates the use of musculoskeletal modeling to estimate strength.•It focuses on the strength variation in diverse hand locations and force directions.•A literature strength database was used as reference for the simulations.•Isometric strength was simulated at 8 hand locations and in 26 exertion directions.•Correlation coefficient of 0.7 was observed between simulated and empirical data.
Increasingly, radiologists' workplaces revolve around PACS and digital imaging. Use of these technologies can lead to repetitive strain injuries, many of which can be exacerbated by specific features ...of a radiology practice environment. Ergonomic approaches, such as proper reading room structure, lighting, temperature, noise, and equipment setup, can help decrease the frequency and severity of repetitive strain injuries and improve radiologist productivity. However, ergonomic approaches are complex, include all aspects of the radiology practice environment, and are best implemented along with proper training of the practicing radiologists. The ergonomic approaches considered most important by members of the ACR Commission on Human Resources are presented in this report, and this information may serve as an aid in departmental planning.
Jewelry production is one of the largest employment sectors in the global economy. This case study focuses on the design of a jewelry-polishing workstation with the objectives of mitigating ...repetitive-motion injuries, improving worker productivity and efficiency, increasing polisher career longevity, and reducing the training time required for new polishers to reach the professional criterion level of production performance. The result is a new polishing workstation that meets the ergonomics and production requirements of jewelry polishers while improving their quality of life and extending the duration of their careers. The polishing station is based on the application of detailed ergonomic and user-centric methodologies.
The employment of Exoskeletons for manual handling work in manufacturing industries aims at increased employment, productivity, safety and security at workplace. This paper highlights several ...challenges, current results and future steps of our work in optimization of Exoskeleton-based factory environments. “JackEx” is the enhancement of the standard digital humanoid “Jack” with concepts and elements of passive Exoskeletons. For the development of JackEx, a new digital manufacturing resource, the intimate coupling of the Exoskeleton digital model to the humanoid “Jack” components was realized. First the CAD model of the Exoskeleton was decomposed in its elementary compound parts, by creating its corresponding kinematic model. As the next step, the coupling of Exoskeleton digital models to the humanoid was a real challenge since the humanoid and Exoskeleton kinematics are heterogeneous and autonomous. In order to define a common kinematic model of humanoid with integrated Exoskeleton, complex calculus and tests were performed resulting in a new kinematic model. JackEx was deeper validated in a virtual and digital environment through real test cases simulations. The comparison between the simulation results with those performed for the same task but without integrated Exoskeleton, revealed from an ergonomically perspective the benefits of employing the Exoskeleton in manufacturing factories.
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