Study on quality improvement of visual, audio and haptic media communications in distributed virtual environments

为了提高分布式虚拟环境中触觉媒体、音视频通信的质量，研究了网络时延、时延抖动和丢包对服务质量的影响，并对服务质量控制进行了研究。由于所需的服务质量取决于不同的应用，我们在本研究中处理了以下四个应用：(1)分布式触觉博物馆为了提供高质量的指导，我们提出了对流解释信息开始的自适应控制。我们还提出了可触摸展品的自适应显示控制。通过实验验证了这两种控制方式的有效性。(2)远程触觉书法教学系统/远程触觉绘画教学系统我们开发了远程触觉书法教学系统和远程触觉绘画教学系统。引入目的地间同步控制，调整多个目的地之间的输出时序，并提出了带预测的目的地间同步控制。(3)触觉媒体音视频传输系统构建了一个用户在观看视频时触摸位于远处的真实对象的流媒体音视频传输系统。研究了三种媒体间的流间同步误差对媒体输出质量的影响。(4)与触觉媒体的协同工作我们考察了触觉媒体的打包间隔以及航位推算的影响。我们还对目标间同步的同步大师方案进行了改进，表明该方案大大提高了输出质量。我们进一步处理了网络实时游戏，并研究了网络延迟对玩家之间公平性的影响。

In order to improve the quality of haptic media, audio and visual communications in distributed virtual environments, we investigated the influences of network delay, delay jitter and packet loss on the quality of service (QoS) and studied QoS control. Since required QoS depends on applications, we dealt with the following four applications in this study.(1)Distributed haptic museumWe proposed adaptic control on streaming start of explanatory information in order to provide high-quality guidance. We also proposed adaptive display control of touchable exhibits. By experiment, we demonstrated the effectiveness of the tow types of control.(2)Remote haptic calligraphy system/remote haptic drawing instruction systemWe developed a remote haptic calligraphy system and a remote haptic drawing instruction system. We introduced inter-destination synchronization control, which adjusts the output timing among multiple destinations, and proposed inter-destination synchronization control with prediction.(3)Haptic media, sound and video transfer systemWe constructed a haotic media, sound and video transfer system which a user touches a real object located at a remote place while watching video. We investigated the influences of inter-stream synchronization errors among three types of media on the media output quality.(4)Collaborative work with haptic mediaWe examined the influence of packetization interval of haptic media as well as dead-reckoning. We also enhanced the synchronization maestro scheme for inter-destination synchronization and illustrated that the scheme improves the output quality largely. We further handled networked real-time games and investigated the influence of network latency on the fairness among players.