Analysis and compensation of operational force in bilateral control systems under time-varying delay

This paper proposes a method to eliminate scratchy feeling in bilateral control systems under time-varying delay. 4-channel bilateral control system is a technique which can transmit haptic sense to remote place with two robots, master and slave. However, when network is used for data transmission, time delay occurs and it degrades the stability of the systems and increases operational force. Furthermore, if the time delay is time-varying, operator feels uncomfortable scratchy sensation in addition to the operational force. Therefore, this paper proposes a method to compensate the effect of time-varying delay in 4-channel bilateral control systems. First, it is cleared that the scratchy feeling can be regarded as high frequency communicative operational force and that it can be calculated in real time quantitatively. Then, elimination method for the scratchy feeling is proposed from the view of operational force. Proposed method can compensate only the effect of delay variation without any delay time model. The validities of proposed methods are verified by some experiments.