Allowable delay between images and tactile information in a haptic interface

In a virtual environment, it is very important for users, to directly manipulate the virtual objects, and we are researching ways to implement force feedback devices in VR environments. In order to provide good interaction, interactive systems must respond to the reactions of users as quickly as possible. However, due to the properties of input devices, output devices and software, lag is inevitable. There is a trade-off between generating highly realistic images and having them synchronize with other information in VR environments. It is necessary to measure allowable delay and how it effects a user´s sensation of realism. There is a lack of information concerning perceptional studies on the delay between visual information and tactile information when force feedback devices are employed. Accordingly, this paper describes the results of tests that measured the allowable delay between images and tactile information via a force feedback device. Two experiments were performed: (1) subjective evaluation in real space and (2) subjective evaluation in a virtual space using a force feedback device