An experimental study on the effects of Network delay in Cooperative Shared Haptic Virtual Environment

Abstract

A cooperative shared haptic virtual environment (CSHVE), where the users can kinesthetically interact and simultaneously feel each other over the network, is beneficial for many distributed VR simulations. A little is known about the influences of the network delay on the quality of haptic sensation and the task performance in such environments. This paper has addressed these issues by conducting a subjective evaluation to the force feedback and the task performance in a tele-handshake cooperative shared haptic system for different delay setting. Also, four subjective measures to evaluate the quality of haptic in CSHVEs have been proposed. These measures are the feeling of force, the consistency between the haptic-visual feedback, the vibration, and the rebound in the haptic device. In addition, a detailed description of the haptic sensation for different time delays is also described. A network emulator was utilized to simulate the real network cloud. An objective evaluation of the force feedback and the performance showed that there was no effect of the delay on the force feedback. It had a negative impact on the task performance. In general, the quality of haptic deteriorated as the delay increased and vibration and rebound hampered the users for large time delay. The haptic-visual consistency was robust in the presented system even for large time delays. Nevertheless, the examined tele-handshake system was able to deliver a high quality of haptic sensation, good performance, and stability for large time delay over the network.