Abstract
The virtual ergonomic assessment based on Digital Hand which estimates grasp posture and evaluates the quality of grasp is valuable for hand-held product design, because it can save the cost of test subjects, time, fabricating physical mockups, and it also enables objective evaluation. In this paper, we propose the method to implement deformable property caused by a contact between Digital Hand and the product surface by modeling the fingers as ″quasi-rigid″ objects, by constructing a physical model based on Boussinesq formula which approximates skin contact deformation mechanism, by detecting collision between Digital Hand and a product surface and enlarging the collision area, and then by finally solving Linear Complementarity Problem to resolve the contact and to produce the visible skin surface deformation. The plausible skin deformation could be obtained, because the method preserved the volume of Digital Hand before and after the skin deformation. In addition, utilizing the locality property of the deformation, the method can be easily used by the existing Digital Hand model and do not affect its original scheme of skin deformation caused by bending the finger.
