Study on Quality of Service Control Schemes in Distributed Virtual Environments Using Haptic Media

作为分布式虚拟环境中的QoS（服务质量）控制，我们解决了媒体同步控制、因果关系控制、流量控制、错误控制等问题。我们还处理了在三维虚拟空间中输出声音和视频的情况，通过在空间中设置多个CC对象，以便将声音和视频与触觉媒体一起处理。首先，我们改进了之前提出的虚拟时间渲染（VTR）算法，用于触觉媒体同步以及触觉媒体与语音之间的同步。通过实验验证了改进算法的有效性。此外，我们还增强了先前提出的用于群体（或目的地间）触觉介质控制的同步大师方案，并通过实验证明了增强同步大师方案的有效性。该方案进一步实现了因果关系控制。接下来，对于触觉介质的流量控制和误差控制，我们重点研究了航位推算。本文提出了一种根据网络时延动态改变航位推算阈值的方案。该方案与上述增强的VTR算法结合使用。通过实验验证了该方案的效果。此外，我们还提出了一种自适应方案，根据网络延迟动态调整计算反力时所用的弹簧模量。通过实验验证了该方案的有效性。实现了三维虚拟空间的立体视觉，阐明了立体视觉效果与网络时延抖动影响之间的关系。此外，我们假设我们在三维虚拟空间中输出语音和视频，并交互移动CC对象。我们提出了一种自适应QoS控制方案，该方案根据网络负载、各终端的CPU负载以及对象的重要性进行媒体同步控制、流量控制、CPU负载控制等。通过实验验证了该方案的有效性。少

As QoS (Quality of Service) control in distributed virtual environments, we addressed media synchronization control, causality control, traffic control, error control, and so on. We also dealt with the case where we output voice and video in a 3-D virtual space by setting multiple CC objects in the space in order to handle voice and video together with haptic media.First, we enhanced the virtual-time rendering (VTR) algorithm, which we previously proposed, for haptic media synchronization and synchronization between haptic media and voice. By experiment, we confirmed the effectiveness of the enhanced algorithm. Also, we enhanced the synchronization maestro, which we previously proposed, for group (or inter-destination), control of haptic media and demonstrated the effectiveness of the enhanced synchronization maestro scheme by experiment. The scheme further carries out the causality control.Next, for traffic control and error control of haptic media, we focused on dead-reckoning. We pr … More oposed a scheme that dynamically changes threshold values of dead-reckoning according to the network delay. The scheme is employed together with the above enhanced VTR algorithm. By experiment, we clarified the effects of the scheme. In addition, we proposed an adaptive scheme that dynamically adjusts the spring modulus employed for calculation of the reaction force according to the network delay. We confirmed the effectiveness of the scheme by experiment. We also realized stereoscopic viewing of a 3-D virtual space and clarified the relation between the effect of stereoscopic viewing and the influence of the network delay jitter.Furthermore, we supposed that we output voice and video in a 3-D virtual space and move CC objects interactively. We proposed an adaptive QoS control scheme, which carries out media synchronization control, traffic control, CPU load control, and so on according to the network load, the CPU load at each terminal, and the importance of objects. By experiment, we illustrated the effectiveness of the proposed scheme. Less