A Study of Perceptual Performance in Haptic Virtual Environments

The performance levels of human subjects in size identification and size discrimination experiments in both real and virtual environments are presented. The virtual environments are displayed with a PHANToM desktop three degree-of-freedom haptic interface. Results indicate that performance of the size identification and size discrimination tasks in the virtual environment is comparable to that in the real environment, implying that the haptic device does a good job of simulating reality for these tasks. Additionally, performance in the virtual environment was measured at below maximum machine performance levels for two machine parameters. The tabulated scores for the perception tasks in a sub-optimal virtual environment were found to be comparable to that in the real environment, supporting previous claims that haptic interface hardware may be able to convey, for these perceptual tasks, sufficient perceptual information to the user with relatively low levels of machine quality in terms of the following parameters: maximum endpoint force and maximum virtual surface stiffness. Results are comparable to those found for similar experiments conducted with other haptic interface hardware, further supporting this claim. Finally, it was found that varying maximum output force and virtual surface stiffness simultaneously does not have a compounding effect that significantly affects performance for size discrimination tasks.