Bilateral control using estimated environmental stiffness as the master position gain

Bilateral control system has been developed as a method to transmit a tactile sense. It enables human operators to feel as if they were really touching the environment. Teleoperation with the bilateral control has a wide range of application such as telesurgery, deep-sea operation, space mission, etc. However, the presence of the communication delay between master and slave systems degrades performance and stability. There are two representative conventional methods based on acceleration control. One is 4ch bilateral control and the other is 3ch bilateral control. In 4ch bilateral control system, an operator is able to feel the hard environment, but the operator feel the large operational force. On the other hand, in 3ch bilateral control system, little operational force is generated, but stable contact can not be achieved. This paper proposes a novel bilateral control using the estimated environmental stiffness as the master position gain. The proposed method enables the operator to feel the hard environment with little operational force. The validity of the proposed control system is confirmed by analyses and experiments.