Kenji Hikichi

The evaluation of delay jitter for haptics collaboration over the Internet

What we are concerned with in this paper is a shared virtual environment (SVE) on a non-dedicated network like the Internet. Especially, we address haptics on an SVE for the new generation of network applications. The goal of our research Is to build an SVE system in which multiple participants can collaborate using haptics feedback, even though the participants are located around the world. One of the problems for this system is network impairment, and we have examined the effect of constant network delay and packet loss on the haptics collaboration system. In this paper we examine and evaluate the effect of delay jitter on the system when using media synchronization and dead reckoning.

Architecture of haptics communication system for adaptation to network environments

Currently network haptic applications become more effective than ever, various usages are being sought in order to improve efficiency and accuracy of tele-operation and communications among users in shared virtual environments (SVEs). The behavior of haptic communication system under realistic network conditions (delay, jitter, and bandwidth limitation) has recently been studied. Therefore the aim of our research is to develop the network-based haptic interaction system which adapts to realistic network environments including the Internet. In this work, we design and implement a prototype of the system with network tolerance in consideration of various network problems. Experiments using objective and subjective evaluations showed that the system works properly under realistic network conditions.

The effect of network delay on remote calligraphic teaching with haptic interfaces

For a design of distributed virtual environments (DVEs) system, it is important to clarify the relation between network-level quality of service (QoS) and user-level QoS. This paper examines network QoS problem on a remote calligraphic teaching system with haptics interfaces, where a pair of users (teacher and student) interact directly (not through any virtual objects), and the operation of haptic device of one user is immediately reflected to another users reaction force. In this system, teacher navigates student to write down the same character on a virtual paper using a constraint force. The constraint force is used to hold the users stylus of haptic device to follow the remote users operation. We propose a new method to generate a constraint force, which enables to hold tightly the remote users stylus with suppressing unexpected vibrations. This system also can show a visual guide, which stands the remote users information (position of the cursor and writing pressure). We carried out subjective evaluation on the system for assessing the effect of network delay between teacher and students hosts. We also compared the effect of force feedback and visual guide in the system to evaluate the role of haptics.

Influence of network delay on ensemble application

Haptic device has been brought to public attention. We are developing networked music ensemble system with haptic devices. Pairs of user connected network play drums. In such systems, the impairment of network QoS such as network delay or packet loss cause degradation of collaboration performance among users. The purpose of this study is to examine the influence of network delay and to examine the effect of distributed synchronization and media synchronization, and to investigate role of haptics for this application in such haptic audio communication system.