Perceptual illusion in virtual reality using haptic interface

Recently, the haptic interface system (one of a variety of force display devices) has attracted great interest as a new virtual reality technology, stimulating vigorous research. Most reports deal with methods of constructing a haptic interface system or the development of new devices having with a particular mechanism, and the various methods suitable for force display. However, it is also necessary to clarify the relationship between the virtual dynamics characteristics of a system and a human being´s feelings in order to present the accurate force sensation from virtual environment. In this paper, we evaluate the force sensations experienced by human beings with the psychological experiments that examine perceptual illusion phenomena, including the horizontal-vertical illusion and the size-weight illusion. These results show that perceptual illusions occurring in a real environment can be also reappeared in a virtual environment. Therefore, perceptual illusions may have the potential for application to virtual reality. Moreover, the characteristics of perceptual illusions can be examined by changing the virtual dynamics parameters of the haptic interface. Finally, this paper shows that the haptic interface is a very effective tool for the investigation of perceptual illusions.