Human Arm simulation for interactive constrained environment design

During the conceptual and prototype design stage of an industrial product, it is crucial to take assembly/disassembly and maintenance operations in advance. A well-designed system should enable relatively easy access of operating manipulators in the constrained environment and reduce musculoskeletal disorder risks for those manual handling operations. Trajectory planning comes up as an important issue for those assembly and maintenance operations under a constrained environment, since it determines the accessibility and the other ergonomics issues, such as muscle effort and its related fatigue. In this paper, a customer-oriented interactive approach is proposed to partially solve ergonomic related issues encountered during the design stage under a constrained system for the operator's convenience. Based on a single objective optimization method, trajectory planning for different operators could be generated automatically. Meanwhile, a motion capture based method assists the operator to guide the trajectory planning interactively when either a local minimum is encountered within the single objective optimization or the operator prefers guiding the virtual human manually. Besides that, a physical engine is integrated into this approach to provide physically realistic simulation in real time manner, so that collision free path and related dynamic information could be computed to determine further muscle fatigue and accessibility of a product designComment: International Journal on Interactive Design and Manufacturing (IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with arXiv:1012.432

Dealing with Modularity of Multibody Models

International audienc

Prediction of lumbar fatigue during gymnastics landings using statistical modelling and Machine Learning

International audienc

Cutting force and EMG recordings for ergonomics assessment of meat cutting tasks:influence of the workbench height and the cutting direction on muscle activation levels

Repetitive arm movement and force exertion are common in meat cutting tasks and often lead to musculosketal disorders. In this study, the effects of the workbench height and the cutting direction on the levels of muscular activation of the upper extremity during meat cutting tasks were investigated. Seven subjects performed 4 trials of 20s each at the 4 different heights (0 cm, −10 cm, −20 cm and −30 cm below the elbow height), alternating two cutting directions. Activation levels of upper extremity muscles (biceps brachii, triceps long head, deltoideus anterior, deltoideus medialis and upper trapezius) and cutting forces were recorded synchronously. Then the trends of the normalized activations with regard to the workplace design parameters (table height and cutting direction) were computed. Results showed that the optimal configuration is a partially related to the task, whereas motor control strategies have also an influence on it. The present results provide new key information about the effects of workbench heights during a repetitive meat cutting task and a complete assessment protocol to analyse workstation design parameters influence on muscles activation levels.</jats:p