Haptic Data Reduction in Time-delayed Teleoperation Based on the Time Domain Passivity Approach

We propose a novel combination of haptic data reduction with the control architecture of the time domain passivity approach (TDPA) in teleoperation systems for dealing with time-varying delay. The sampling rate of haptic data is typically 1kHz for stability and transparency reasons. This high packet rate as well as the additional data overhead becomes a critical factor for data transmission in a packet-switched communication network. On the other hand, passivity-based control architecture needs to be employed to guarantee system stability, when communication delay exists. In this paper, we develop a TDPA-based haptic data reduction approach to reduce the packet rate over the communication network while preserving system stability in the presence of varying communication delays. Compared to the existing wave variable-based (WVbased) haptic data reduction approaches, our proposed scheme has smaller distortion in force signals and is flexible and robust to time-varying delays. Experiments show that our proposed approach can reduce the packet rate up to 80%, without introducing significant distortion. In addition, the proposed approach outperforms the existing WV-based approach in both packet rate reduction and subjective preference for delays up to 100ms± 30ms.