Improving Haptic Feedback Fidelity in Wave-Variable-Based Teleoperation Orientated to Telemedical Applications

In wave-variable-based teleoperation systems, under the condition of time delays, the perceived haptic feedback by the user is deteriorated by a bias term due to the communication nature of wave variables. Orientated to telemedical applications, this paper proposes a new method that can partially cancel the bias portion, so that the fidelity of haptic feedback is improved. Specifically, the returning wave is augmented by the difference between the velocity of the master and the desired velocity of the slave. The steady-state position tracking is not affected by the modification. The passivity of the augmented teleoperation system can be maintained by tuning the bandwidth of a low-pass filter. Hence, stability is always achievable. The experiment results demonstrate the effectiveness of the scheme.