Hierarchical bilateral control for haptic systems with different degree-of-freedom

Haptic information has been attracting the attention as the third media following hearing, sight. The haptic information is effective for medical and industry. In conventional research of haptics, low degrees of freedom system is often used. However, to transmit human-like haptic information, human type robot should be used. In this research, a finger type robot with 10 degrees of freedom is used as slave system to transmit haptic information. This robot is chain driven robot. This structure can transmit better haptic sense than serial link robot because the inertia of each joint is low and gear ratio of motor is low. When human grips something by hand robot, it is thought that grip force can be simplified to one degree of freedom force. Thus, in this research, the hand robot as slave system and one degree freedom linear motors are used as master system for the simplicity of system setup. The system of this research is constructed with different degree of freedom robot. To transmit haptic sense this system, hierarchical bilateral control is proposed. The control method realizes transmission of haptic sensations between systems with the different degree of freedom. By the experiments, viability of proposed method is confirmed.