The virtual product development is the unified process of product design, evaluation and validation. Ergonomics analysis is the important step for product validation in the process, and the virtual human is key to the computer-aided product ergonomics. In this paper, ergonomics simulation system is studied based on some elements of ergonomics analysis and assessment. An ergonomics virtual human is built, which is a unified framework made up of biomechanics/physiology-based model, anthropometrical model, posture and motion model, task model, human reactions and decision-making model and human factor analysis model. The framework is applied to virtual prototyping and virtual product development.
Since 1940s, human capability and limits have been studied, but their importance has not been recognized until 1980s. Recently, the development of product design impulses the research on relations between human, machine and environment. It brings ergonomics to a practicable stage, especially in rehabilitation aids design (Beitler, Harwin, & Mahoney, 1996), aerospace product design (Bennett, 1996) and workplace task ergonomics analysis (Rajan, Kadiresan, & Jeffrey, 1999). With the development of supercomputing, computer graphics, virtual reality and high performance graphics system, the research on ergonomics is extended to virtual environment design platform that is based on 3D-graphics, interactive, physics-based model, and provides real-time simulation and evaluation (Arzi, 1997). In virtual assembly (Rajan et al., 1999), pipeline design (de Sa & Zachmann, 1999), virtual training (Stuering & Schumann, 1999), verification of maintenance processes and others, it has been applied and incorporated in the framework of virtual prototype development. As a key step of product life cycle, it is very important for ergonomics simulation to shortcut test/development cycles, lower development costs, improved quality and enhance safety (Bennett, 1996 and Weyrich and Drews, 1999).
Ergonomic simulation based on virtual human model is brought into life cycle of product development, and to be an important part of virtual product development. In product ergonomics, that is applied to prototype testing of assembly, maintenance, safety, and so on. In production ergonomics, job intensity, manual handling limits, fatigue/recovery time is simulated and optimized. In job training, safety is improved and expense is reduced. The key to ergonomic simulation is visualizing, interacting and coordinating, the distributed ergonomic simulation based on shared view is our further research. Distributed communication phases of avatar and task multipoint coordination are higher level of ergonomics virtual human model to research.
