Transmission control in multilateral system for teletraining

Recently, preservation of the skills of experts has become a serious problem in the medical and production fields. It is difficult to acquire human motion, including touching motion, by means of a conventional visual-based system. Touching motion is inherently bilateral, since an action is always accompanied by a reaction. Bilateral force feedback control is necessary to acquire another person's skill. This paper proposes a haptic teletraining system using multilateral force feedback control. Since the multilateral control transmits haptic information among three or more remote systems, it is possible to train multiple remote trainees simultaneously using one skilled trainer. In the proposed haptic teletraining system, each local system consists of a master-slave system. Since a touching motion is subject to the law of action and reaction, it is possible to decompose the force information into an action force and a reaction force by using bilateral control. Thus, the skilled motion of a trainer is acquired and saved as a digital database integrated with his haptic information. The proposed system is applied to a one-trainer/two-trainee system. As a result, motion including contact with the environment is transmitted and trained with vivid force feedback. The experimental results show the viability of the proposed method.