Modelling the human upper body in three-dimensional motion

摘要

A six-link model representing the human upper body and arm was developed. A set of joint restraints based on the ergonomic ranges of joint angles has been applied to allow the synthesis of upper body motion. Using anthropometric information for scaling subject size and mass parameters, an inverse dynamic model of arms and the thorax is employed to determine the necessary joint moments for the desired trajectory and speed of the hand. Acceleration profiles along the proposed trajectory allow the full synthesis of a motion for a human performing a simple pick-and-place task. Three-dimensional data was gathered for a human subject performing the same task. The trajectory naturally used by the human subject and the trajectory hypothesized for the synthesis is compared and differences are analyzed. Changes in trajectory used by the human subject as a result of changes in workstation geometry were analyzed. The joint moments resulting from the trajectory used by the human subject were compared to those generated by the computer synthesis using the linkage model. Joint moments required by the human were found to be less smooth than those of the synthesis and to have peak values significantly larger than those of the synthesis.