Abstract
In this paper, we propose a new formulation of the dynamics of human figures, which are characterized by their frequent contact with the environment and underactuation due to the free joint of the body link. The formulation is shown to have wide variety of applications from dynamics simulation to generation of physically consistent motions of underactuated systems including human figures, meaning that the proposed formulation gives a common basis for the problems concerning motions of human figures. The computational method of simulating collisions and contacts itself has advantages compared to previous methods: efficiency and stiffness of computation are achieved by two factors, that is, (1) to apply rigid contact model instead of spring-damper model in which extremely large collision and contact forces are applied to make the computation instable, and (2) to avoid the inequality conditions of contact forces used in conventional rigid contact model approaches, leading to quite simple and efficient solution.
