Multi-degree-of-freedom motion-copying system considering variation in friction

This paper proposes a motion-reproduction method for a multi-degree-of-freedom system. For storing and reproduction of haptic information, a motion-copying system was proposed. Reproducing the saved motion using this method is difficult when the environmental configuration in the motion-loading phase is different from that in the motion-saving phase. There are several methods for adapting to the variation in environmental configuration. In the conventional method, it is considered that the orthogonal axes are controlled independently. However in the tracing motion, friction and interference exist between the orthogonal axes. Thus, it is impossible to reproduce the saved motion when the coefficient of friction varies. In this paper, friction in a two degree-of-freedom system is modeled and a motion-copying system using the modeled friction is proposed. The proposed method reproduces the saved motion even when the coefficient of friction varies. To validate the proposed method, experiments were conducted.