Variable tension control for master-slave tendon-driven robot hand

The teleoperation using a multi-degree of freedom tendon-driven robot hand is suitable for human support because intuitive operations can be conducted. In the teleoperation, bilateral control is used to transmit tactile sensation. It is necessary for bilateral control to achieve high operationality and high resonant frequency of force control at one time. Unfortunately, in the tendon-driven system, operationality and resonant frequency of force control are affected by wire tension. Low tension force is better to get high operationality. On the other hand, resonant frequency of force control becomes higher as the tension force increases. Therefore, in this paper, variable tension control is proposed to improve the performance of the tendon-driven bilateral control. Variable tension commands are derived from the joint torque responses. High operationality can be achieved in free motion and high resonant frequency of force control can be achieved in contact motion. The validity of the proposed method was confirmed through experiments of bilateral control.